OFFSET
0,3
LINKS
Robert Israel, Table of n, a(n) for n = 0..5160
EXAMPLE
B(5,x) = x^5 - 5/2*x^4 + 5/3*x^3 + 0*x^2 - 1/6*x + 0 hence a(5) = 3
MAPLE
f:= proc(n) local B;
B:= bernoulli(n, x);
nops(select(t -> coeff(B, x, t)::integer, [$0..degree(B)]))
end proc:
map(f, [$0..100]); # Robert Israel, Aug 28 2018
MATHEMATICA
a[n_] := Select[CoefficientList[BernoulliB[n, x], x], IntegerQ] // Length;
a /@ Range[0, 100] (* Jean-François Alcover, Aug 26 2020 *)
PROG
(PARI) B(n, x)=sum(i=0, n, binomial(n, i)*bernfrac(i)*x^(n-i)); a(n)=sum(i=0, n, if(frac(polcoeff(B(n, x), i)), 0, 1))
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Jun 19 2004
STATUS
approved
