[seqfan] Self-describing chunks of primes

Eric Angelini Eric.Angelini at kntv.be
Sat Nov 30 18:28:37 CET 2013

Hello SeqFans,
We want the first permutation of the 
integers >0 describing its chunks
of primes (separated by non-primes):


If we mark the non-primes of S we get:


And if we make the count of the non-
marked integers we get successively:

1 integer [the "2"]
2 integers ["3" and "5"]
4 integers ["7,11,13,17"]
3 integers["19,23,29"]
5 integers ["31,37,41,43,47"]
etc. -- said integers being the primes
in their natural order, marked integers
being the non-primes in their natural 
order and the first column above being
the sequence S itself.


The equivalent T seq where the roles are
reversed seems to start like this:


Marking the primes:


Computing the size of each "non-prime chunk" gives:


... which is T itself.

None of those seq are in the OEIS, I think.

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