A166140 Product of the nonzero elements of the n-th row of A166139.

1, 2, 3, 2, 5, 6, 7, 2, 3, 10, 11, 6, 13, 14, 15, 2, 17, 6, 19, 10, 21, 22, 23, 6, 5, 26, 3, 14, 29, 900, 31, 2, 33, 34, 35, 6, 37, 38, 39, 10, 41, 1764, 43, 22, 15, 46, 47, 6, 7, 10, 51, 26, 53, 6, 55, 14, 57, 58, 59, 900, 61, 62, 21, 2, 65, 4356, 67, 34, 69, 4900, 71, 6, 73, 74, 15

Offset: 1

Author

Mats Granvik, Oct 08 2009

Keywords

• nonn

Comments

Differs from A007947 at n = 30.

Crossrefs

Cf. A166139, A014963.

Programs

Maple

A080305 := proc(n) if numtheory[mobius](n) < 0 then n; else 1; end if; end proc:
A126988 := proc(n,k) if n mod k = 0  then n/k ; else 0; end if; end proc:
A166139 := proc(n,k) A080305(A126988(n,k)) ; end proc:
A166140 := proc(n) a := 1 ; for k from 1 to n do if n mod k = 0 then a := a* A166139(n,k) ; end if; end do: a ; end proc:
seq(A166140(n),n=1..75) ; # R. J. Mathar, May 30 2011

Mathematica

A080305[n_]:= If[MoebiusMu[n]<0,n,1];
A126988[n_,k_]:=If[Mod[n, k]==0, n/k, 0];
A166139[n_,k_]:=A080305[A126988[n,k]];
A166140[n_]:= (p=1; For[k=1, kA166139[n,k]]]; p)
Table[A166140[n], {n,100}] (* Jon Maiga, Jan 10 2019 *)