|
%I #20 Jun 09 2023 21:42:06
%S 1,3,9,1,315,3855,13797,1,4,34636833,3,163,5,25,60,1525,
%T 18900352534538475,1445580,1609,3,17,1,3477359660913989536233495,59,
%U 36793758459,12379533,758220919762679268184943973309,3421967,15
%N Least k such that (2*p_n)*k + 1 | Mersenne(p_n), p_n = n-th prime, n >= 2.
%C M(p_n) = 2^p_n - 1 = (2*p_n)*j + 1 = [(2*p_n)*k_1 + 1] ... [(2*p_n)*k_i + 1], n >= 2 (i.e., odd prime p_n), i >= 1. Then k = Min(k_1, ..., k_i).
%H Chris K. Caldwell, <a href="https://t5k.org/notes/proofs/MerDiv.html">Modular restrictions on Mersenne divisors</a>
%F a(n) = (A016047(n) - 1) / (2*A000040(n)). - _Jeppe Stig Nielsen_, Jul 18 2014
%Y Cf. A000040, A016047.
%K nonn
%O 2,2
%A _Robert G. Wilson v_
%E Definition edited, comment added by _Daniel Forgues_, Oct 06 2009
|
