OFFSET
0,2
COMMENTS
LINKS
Wolfdieter Lang, On Sums of Powers of Arithmetic Progressions, and Generalized Stirling, Eulerian and Bernoulli numbers, arXiv:1707.04451 [math.NT], 2017.
FORMULA
EXAMPLE
The rationals r(n) begin: 1, -2, 8/3, 0, -128/15, 0, 2048/21, 0, -32768/15, 0, 2621440/33, 0, -5796528128/1365, 0, 939524096/3, 0, -7767448354816/255, 0, 1507258642989056/399, 0, -95993412418797568/165, ...
MAPLE
seq(numer(4^n*bernoulli(n)), n=0..28); # Peter Luschny, Jul 17 2017
MATHEMATICA
Table[4^n BernoulliB[n] // Numerator, {n, 0, 30}] (* Jean-François Alcover, Jul 14 2018 *)
PROG
(PARI) a(n) = numerator(4^n*bernfrac(n)); \\ Michel Marcus, Jul 06 2017
(Python)
from sympy import bernoulli
def a(n): return (4**n * bernoulli(n)).numerator()
[a(n) for n in range(31)] # Indranil Ghosh, Jul 06 2017
CROSSREFS
KEYWORD
sign,frac,easy
AUTHOR
Wolfdieter Lang, Jul 05 2017
STATUS
approved