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 A091398 a(n) = Product_{ p | n } (1 + Legendre(5,p) ). 2
 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 2, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,11 LINKS Andrew Howroyd, Table of n, a(n) for n = 1..1000 MAPLE with(numtheory); L := proc(n, N) local i, t1, t2; t1 := ifactors(n)[2]; t2 := mul((1+legendre(N, t1[i][1])), i=1..nops(t1)); end; [seq(L(n, 5), n=1..120)]; MATHEMATICA a[n_] := Times @@ (1+KroneckerSymbol[5, #]& /@ FactorInteger[n][[All, 1]]); Array[a, 105] (* Jean-François Alcover, Apr 08 2020 *) PROG (PARI) a(n)={my(f=factor(n)[, 1]); prod(i=1, #f, 1 + kronecker(5, f[i]))} \\ Andrew Howroyd, Jul 23 2018 CROSSREFS Cf. A080891, A091379, A091396. Sequence in context: A087781 A181009 A270599 * A062103 A112314 A280799 Adjacent sequences:  A091395 A091396 A091397 * A091399 A091400 A091401 KEYWORD nonn,mult AUTHOR N. J. A. Sloane, Mar 02 2004 STATUS approved

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Last modified April 18 15:54 EDT 2021. Contains 343089 sequences. (Running on oeis4.)