True, and I must admit that I am bored with this.
The array sum changes after the first or second sequence or after each sequence. This also happens in my sleek patch: https://forum.pdpatchrepo.info/topic/15834/shuffling-audio-only-allowing-repeats-once-all-options-have-been-played/11

I think OPs requirement has been solved by your patch or others in the thread?

Also permutations have been discussed in this forum before:
https://forum.pdpatchrepo.info/topic/10707/all-possible-permutations-with-repetitions-of-harmonic-volume-from-top-to-bottom/8

https://forum.pdpatchrepo.info/topic/10746/permutations-second-part-can-anybody-get-this-patch-to-work

(I did not read them entirely)

And there are non-Vanilla externals, mentioned in Dizzys thread and fd_lib [combi], an object I don't understand yet.

EDIT and this https://forum.pdpatchrepo.info/topic/5142/generating-all-possible-permutations-of-a-fixed-number-set
and that
https://grrrr.org/2010/11/04/list-permutation-pure_data/

This probably comes closer, a new sequence has all the possibilities but the last number of the last sequence. A new permutation.

randompermutations2.pd

@jameslo wrote:

I also wonder if it's not the worst idea to just generate random permutations and simply throw out the ones you don't like, e.g. ones that start with the same # as the end of the previous permutation.

Yes I think it is not the worst idea!

EDIT: patch does not work https://forum.pdpatchrepo.info/topic/15858/shuffling-in-pd-vanilla

There was a little bug: The center output of [list split] needs a [route bang] (as I read in the helpfile now.
randomwmemory.pd

randomwmemory.pd

There are many ways to do this ... @Dizzy-Dizzy Please read the patches and try to understand them.

https://forum.pdpatchrepo.info/topic/14635/how-to-construct-a-background-noise-filter-in-pd

If non-Vanilla externals are ok: zexy/urn
Otherwise for example:
random-wo-repitition.pd
(not cheap!)
With that for example:
https://forum.pdpatchrepo.info/topic/14522/is-it-possible-to-group-different-soundfiles-in-only-one-message/2

[list-find] from list-abs library

What are you referring to by normalize action?
normalize message to an array?
Pd is deterministic! See 2.control.examples/08.depthfirst.pd