OFFSET
1,2
FORMULA
E.g.f: (log(1 - x) - x*log(1 - x^2))/(x - 1). - Benedict W. J. Irwin, Apr 25 2017
MATHEMATICA
Rest@Table[CoefficientList[Series[(Log[1-x]-x*Log[1-x^2])/(x-1), {x, 0, 20}], x][[n]](n-1)!, {n, 1, 20}] (* Benedict W. J. Irwin, Apr 25 2017 *)
PROG
(PARI) a(n) = n! * sum(k=ceil(n/2), n, 1/k); \\ Michel Marcus, Apr 25 2017
(Python)
import math
from sympy import factorial
def a(n): return factorial(n)*sum([1/k for k in range(int(math.ceil(n/2)), n + 1)]) # Indranil Ghosh, Apr 25 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Ralf Stephan, Dec 10 2004
STATUS
approved