[seqfan] Re: More first differences -- with composites (corrected) (2)
Eric Angelini
Eric.Angelini at kntv.be
Thu Jun 20 15:17:06 CEST 2013
... or better, try to subtract first, then add...
(sorry -- this is obvious for me, not at all for
the "normal" reader)
best,
É.
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... correction hereunder, of course:
> S starts with a(1)=1, then we always try to add
should be:
> S starts with a(1)=1, then we always try to add
or subtract (...)
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Hello SeqFans,
is S the "equivalent" of http://oeis.org/A109888
if we drop the "strictly increasing" constraint?
S=1,9,15,25,21,33,49,35,55,...
S starts with a(1)=1, then we always try to add
to a(n) the smallest composite:
- not yet in S;
- not yet in the first differences of S;
- not producing a prime.
S = 1, 9, 15, 25, 21, 33, 49, 35, 55,...
diff: 8 6 10 4 12 16 14 20
As usual, S, merged with its first differences,
is conjectured to be a permutation of the non-primes.
Best,
É.
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