Some numbers

[Lootman]

Not really a puzzle, more a riddle, in the sense that I do not know the answer, nor even know that there necessarily is one. But I am curious after seeing these numbers displayed recently on a visit to Cambridge.

Is there any significance (mathematical or otherwise) to the following set of numbers?

1, 5, 8, 10, 37, 41, 42, 50, 68.

[swill453]

A list of buses?

Scott.

[Laughton]

Where abouts were they displayed (what sort of display rather than the name of the street where you saw the display)?

[swill453]

Winning lottery numbers? Page numbers in a book?

[Lootman]

Where abouts were they displayed (what sort of display rather than the name of the street where you saw the display)?

It was a piece of art. The artwork displayed a set of what looked like authentic UK postage stamps from a few decades ago. (It was a younger looking image of QE2 and yet this was post-decimalisation, so I would estimate it as mid to late 1970s).

Anyway the numbers I cited were the denominations in pence of the stamps displayed. The viewer is invited to think that these were the only denominations available at that time, although of course that may be completely untrue.

It made me think that someone has to come up with what denominations of stamps to offer for sale. You don't want or need to have 99 denominations and so there must be a set of numbers that enable any postage amount from 1p to 99p to be covered, with the minimum number of stamps needed. No more than 5 perhaps?

I guess it is the same issue for coins although they are reusable whereas stamps are usually only used once and are then done, meaning it makes sense to produce them as cheaply as possible, and limiting the denominations available is one way to do that.

Of course the numbers chosen could just be random, and perhaps the purpose of the artist was/is to make the viewer look for meaning where in fact there is none.

[mark88man]

The differences between successive numbers are quite erratic, to me that rules out any mathematical basis for the sequence - even the differences between the differences and so on offer no help.

I remember from helping my dad out with his office postings (letters and small parcels) in the mid-late 70s that there were a wide range of stamp values which while mathematically suboptimal to cover all possible integer values - may have been chosen to reflect and optimise against the then in force costs (1st class, 2nd class, small, large, parcel...)

It may be a bit of research in that direction may find a year when those values were literally the ones available at a PO

[mark88man]

The middle part of your question about minimum number of stamps intrigued me - I googled and found an answer on quora for 1p - 100p

"We can go from lower end to higher end, in steps of 2 (ie binary) : 1, 2, 4, 8, 16, 32 and 37 ——- Total 100. Here, we require 7 stamps.

We can go from higher end to lower end, by halving: Here we start with 50 (100/2), 25, 13, 6, 3, 2, 1 ——- Total 100
Also 7 Stamps"

However although these are complete if the cost of a first class stamp was eg 31 then the top weighting would require 5 stamps and the bottom only 2. So some efficiency against the actual cost would be required

[mc2fool]

It was a piece of art. The artwork displayed a set of what looked like authentic UK postage stamps from a few decades ago. (It was a younger looking image of QE2 and yet this was post-decimalisation, so I would estimate it as mid to late 1970s).

Any chance of a link to an image, or if it was street art, a google street viewable location?

[Lootman]

It was a piece of art. The artwork displayed a set of what looked like authentic UK postage stamps from a few decades ago. (It was a younger looking image of QE2 and yet this was post-decimalisation, so I would estimate it as mid to late 1970s).

Any chance of a link to an image, or if it was street art, a google street viewable location?

This may sound lame but I have never shown an image on TLF, so have no idea how to do that. Other bits of software have a paper-clip button for attachments, but not TLF.

I do have a pic on my phone and can migrate it to my laptop. But that is where things get confusing.

But a good point that it might be the array of images that is significant and not the nominal values.

[mc2fool]

Any chance of a link to an image, or if it was street art, a google street viewable location?

This may sound lame but I have never shown an image on TLF, so have no idea how to do that. Other bits of software have a paper-clip button for attachments, but not TLF.

I do have a pic on my phone and can migrate it to my laptop. But that is where things get confusing.

But a good point that it might be the array of images that is significant and not the nominal values.

You can't upload images to TLF, you have to upload them to somewhere else and then either provide a link or use Img to link it into a post.

A very commonly used free upload site is https://imgur.com/. You don't need to sign up, although doing so gives you control of the images you post (otherwise they're "just there")

So, having got the image on your laptop, go to https://imgur.com/ and (whether you sign up or not), click New post. It will ask you for the image to upload and you can either drag'n'drop the file onto it or click "Choose Photo/Video" and go through the usual file selection popup.

Having uploaded it the simplest thing to then do is to move the mouse over the image and click on the "..." at the top right and select "Get share links", and then in the popup that appears click "Copy Link" next to the "BBCode (Forums)" entry. You can the paste directly into a TLF post you're writing, and voila (do a Preview to check )

The only possible issue is that TLF has a maximum height for images of, IIRC, 1024 pixels, so you might have to scale it down, which you can do with the standard windows image viewer.

[jfgw]

They are all values that have existed, but that is not saying much. All values up to 14p have existed in 1/2p increments, and all integer values up to 20p.

There is a list here, https://en.wikipedia.org/wiki/List_of_Machin_stamps. The values in question do not all relate to the same first issue date. It would be interesting to see which colours they were.


Julian F. G. W.

[staffordian]

For what it's worth, the price of first and second class postage was 10p and 8p respectively, only in 1979. Both numbers are in Lootman's list so this might date it. Other values in the list being smaller to make up different values, or larger for heavier letters etc.

[9873210]

It made me think that someone has to come up with what denominations of stamps to offer for sale. You don't want or need to have 99 denominations and so there must be a set of numbers that enable any postage amount from 1p to 99p to be covered, with the minimum number of stamps needed. No more than 5 perhaps?

Covering all possible values efficiently is not the goal. Some values are much more common than others. First and second class letters, air mail, post cards, second oz supplements, supplemental values for old postage stamps after rate changes, etc. At any particular time you'll probably find that a couple of values are 90% of usage and less than a dozen are 99% of the usage. You efficiently cover these by issuing stamps in these particular denominations.

Uncommon values that did crop up were done using multiple stamps that exist for other reasons. Possibly including a bunch of 1/2p stamps. Which is what I did when as a poor student I "inherited" a box of assorted stamps that had been acquired over the years and had many odd values. It helps to use large envelopes.