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 A166140 Product of the non-zero elements of the n-th row of A166139. 3

%I

%S 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,

%T 29,900,31,2,33,34,35,6,37,38,39,10,41,1764,43,22,15,46,47,6,7,10,51,

%U 26,53,6,55,14,57,58,59,900,61,62,21,2,65,4356,67,34,69,4900,71,6,73,74,15

%N Product of the non-zero elements of the n-th row of A166139.

%C Differs from A007947 at n = 30.

%p A080305 := proc(n) if numtheory[mobius](n) < 0 then n; else 1; end if; end proc:

%p A126988 := proc(n,k) if n mod k = 0 then n/k ; else 0; end if; end proc:

%p A166139 := proc(n,k) A080305(A126988(n,k)) ; end proc:

%p 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:

%p seq(A166140(n),n=1..75) ; # R. J. Mathar, May 30 2011

%Y Cf. A166139, A014963.

%K nonn

%O 1,2

%A _Mats Granvik_, Oct 08 2009

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