A096308 a(n) = Sum_{d divides n} (-1)^(n-d)*Stirling1(n,d).

1, 2, 3, 18, 25, 620, 721, 24878, 158445, 1658782, 3628801, 429976228, 479001601, 26820722994, 639056694705, 10758464202978, 20922789888001, 3774016217836154, 6402373705728001, 1535093032367692372, 17443309565597717361, 237373353486966539746

Offset: 1

Author

Vladeta Jovovic, Aug 01 2004

Keywords

• easy
• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..450

Programs

Maple

a:= n-> add(abs(Stirling1(n, d)), d=numtheory[divisors](n)):
seq(a(n), n=1..23);  # Alois P. Heinz, May 10 2019

Mathematica

f[n_] := Sum[ If[ Mod[n, d] == 0, (-1)^(n - d)StirlingS1[n, d], 0], {d, n}]; Table[ f[n], {n, 20}] (* Robert G. Wilson v, Aug 12 2004 *)

Extensions

More terms from Robert G. Wilson v, Aug 12 2004