%I #23 May 13 2020 08:51:06
%S 5,5,7,5,5,7
%N a(n) is the smallest prime p such that p^4 divides the numerator of the Bernoulli number B(A122272(n)).
%C The numbers m in A122272 are such that the numerator of the Bernoulli number B(m) is divisible by p^4, where p is a prime. For m = 6250, we have that the numerator of B(6250) is divisible by 5^5.
%H The Bernoulli Number Page, <a href="https://www.bernoulli.org/download/bn_factors.txt">Table of factors of the numerators of Bernoulli numbers Bn in the range n = 2..10000</a>, 2018.
%H S. S. Wagstaff, Jr, <a href="http://www.cerias.purdue.edu/homes/ssw/bernoulli/bnum">Prime factors of the absolute values of Bernoulli numerators</a>, 2018.
%Y Cf. A000367, A090987, A090997, A122270, A122271, A122272.
%K nonn,more
%O 1,1
%A _Alexander Adamchuk_, Aug 28 2006
%E Various sections edited by _Petros Hadjicostas_, May 12 2020