A185291 Dirichlet convolution of A000001 with itself.

1, 2, 2, 5, 2, 6, 2, 14, 5, 6, 2, 18, 2, 6, 4, 42, 2, 18, 2, 18, 6, 6, 2, 58, 5, 6, 14, 16, 2, 18, 2, 150, 4, 6, 4, 60, 2, 6, 6, 56, 2, 24, 2, 16, 10, 6, 2, 202, 5, 18, 4, 18, 2, 58, 6, 52, 6, 6, 2, 66, 2, 6, 16, 717, 4, 18, 2, 18, 4, 18, 2, 218, 2, 6, 12

Offset: 1

Author

Ben Branman, Jan 25 2012

Keywords

• nonn

Links

• G. C. Greubel, Table of n, a(n) for n = 1..1000
• Eric Weisstein's World of Mathematics, Dirichlet Series Generating Function.
• Eric Weisstein's World of Mathematics, Finite Group.

Programs

Mathematica

con[f_, g_, x_] := Sum[f[k] g[x/k], {k, Divisors[x]}];Table[con[FiniteGroupCount, FiniteGroupCount, x], {x, 1, 100}]

PARI

DC(a,b)=vector(min(#a,#b),n,sumdiv(n,d,a[d]*b[n/d]))
A185291=DC(A1,A1) /* where A1 is a vector of the first values of A000001 */ - M. F. Hasler, Jan 26 2012

Extensions

Data and Mmca code corrected by M. F. Hasler, Jan 26 2012