[seqfan] a special subsequence(?) of A245594

Max Alekseyev maxale at gmail.com
Mon Oct 10 03:18:01 CEST 2016


SeqFans,

I've encountered what may be a very special subsequence of A245594 (Numbers
n such that n divides 2^n + 10.)

It is constructed by interating the function f(x) = 2^(x-1) + 5 starting at
x = 3 (and so it's somewhat similar to A219037).

The first four terms are 3, 2^(3-1)+5 = 9, 2^(9-1) + 5 = 261, 2^(261-1) +
5, and they all belong to A245594.
It is not yet clear though if the next term also belongs to A245594.

See discussion at MathOverflow: http://mathoverflow.net/q/251717/7076

Regards,
Max



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