OFFSET
0,8
COMMENTS
Also the smallest prime factor of A246006(n) that is >= n+2.
a(n) = 1 iff n is in the set {0, 1, 2, 3, 4, 5, 6, 8, 10, 14}.
a(189) is currently unknown; a(190)..a(199) = {5101, 559570609330768709, 40833790860803270336710504624737304862569304959957, 311, 467, 34110029, 461, 26034939865747697437451558982836040663625026070193, 34470847, 1879}.
All terms are Bernoulli or Euler irregular primes.
LINKS
Eric Chen, Table of n, a(n) for n = 0..188
Samuel Wagstaff, Factorization of Bernoulli and Euler numbers
MATHEMATICA
a246006[n_] := If[EvenQ[n], Abs[Numerator[BernoulliB[n]]], Abs[EulerE[n-1]]];
a241601[n_] := a246006[n]/GCD[a246006[n], n!]
a = {}; Do[a = Append[a, FactorInteger[a241601[n]][[1, 1]]], {n, 0, 99} ]; a
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric Chen, Dec 15 2014
STATUS
approved