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 A166140 Product of the nonzero elements of the n-th row of A166139. 3
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Differs from A007947 at n = 30. LINKS 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, k

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Last modified May 7 20:36 EDT 2021. Contains 343652 sequences. (Running on oeis4.)