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%I #37 May 14 2024 17:50:46
%S 32,284,37580,1072544,55777784,325656968,42764158652,2444284077476,
%T 46872402575720,4093248733492712,167845040875289732,
%U 4841789050865438960,235423026877046134208,7818983737604766777920,95503904455394036720840,6908622244227620311285724,114945213060615779807957456
%N Least even integer k such that numerator(B_k) == 0 (mod 37^n).
%C 37 is the first irregular prime. The corresponding entry for the second irregular prime 59 is A299466, and for the third irregular prime 67 is A299467.
%C The p-adic digits of the unique simple zero of the p-adic zeta function zeta_{(p,l)} with (p,l)=(37,32) were used to compute the sequence (see the Mathematica program below). This corresponds with Table A.2 in Kellner (2007). The sequence is increasing, but some consecutive entries are identical, e.g., entries 18 / 19 and 80 / 81. This is caused only by those p-adic digits that are zero.
%H Bernd C. Kellner and Robert G. Wilson v, <a href="/A251782/b251782.txt">Table of n, a(n) for n = 1..100</a>
%H Bernd C. Kellner, <a href="http://bernoulli.org/">The Bernoulli Number Page</a>
%H Bernd C. Kellner, <a href="https://doi.org/10.1090/S0025-5718-06-01887-4">On irregular prime power divisors of the Bernoulli numbers</a>, Math. Comp. 76 (2007), 405-441; arXiv:<a href="https://arxiv.org/abs/math/0409223">0409223</a> [math.NT], 2004.
%F Numerator(B_{a(n)}) == 0 (mod 37^n).
%e a(3) = 37580 because the numerator of B_37580 is divisible by 37^3 and there is no even integer less than 37580 for which this is the case.
%t p = 37; l = 32; LD = {7, 28, 21, 30, 4, 17, 26, 13, 32, 35, 27, 36, 32, 10, 21, 9, 11, 0, 1, 13, 6, 8, 10, 11, 10, 11, 32, 13, 30, 10, 6, 8, 2, 12, 1, 8, 2, 5, 3, 10, 19, 8, 4, 7, 19, 27, 33, 29, 29, 11, 2, 23, 8, 34, 5, 8, 35, 35, 13, 31, 29, 6, 7, 22, 13, 29, 7, 15, 22, 20, 19, 29, 2, 14, 2, 2, 31, 11, 4, 0, 27, 8, 10, 23, 17, 35, 15, 32, 22, 14, 7, 18, 8, 3, 27, 35, 33, 31, 6}; CalcIndex[L_, p_, l_, n_] := l + (p - 1) Sum[L[[i + 1]] p^i , {i, 0, n - 2}]; Table[CalcIndex[LD, p, l, n], {n, 1, Length[LD] + 1}] // TableForm
%Y Cf. 2*A091216, 2*A092230, A189683, A299466, A299467.
%K nonn
%O 1,1
%A _Bernd C. Kellner_ and _Robert G. Wilson v_, Dec 08 2014
%E Edited for consistency with A299466 and A299467 by _Bernd C. Kellner_ and _Jonathan Sondow_, Feb 20 2018