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%I A016048 #20 Jun 09 2023 21:42:06
%S A016048 1,3,9,1,315,3855,13797,1,4,34636833,3,163,5,25,60,1525,
%T A016048 18900352534538475,1445580,1609,3,17,1,3477359660913989536233495,59,
%U A016048 36793758459,12379533,758220919762679268184943973309,3421967,15
%N A016048 Least k such that (2*p_n)*k + 1 | Mersenne(p_n), p_n = n-th prime, n >= 2.
%C A016048 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 A016048 Chris K. Caldwell, <a href="https://t5k.org/notes/proofs/MerDiv.html">Modular restrictions on Mersenne divisors</a>
%F A016048 a(n) = (A016047(n) - 1) / (2*A000040(n)). - _Jeppe Stig Nielsen_, Jul 18 2014
%Y A016048 Cf. A000040, A016047.
%K A016048 nonn
%O A016048 2,2
%A A016048 _Robert G. Wilson v_
%E A016048 Definition edited, comment added by _Daniel Forgues_, Oct 06 2009

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