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 A185276 Kronecker symbol (-100 / n). 1
 1, 0, -1, 0, 0, 0, -1, 0, 1, 0, -1, 0, 1, 0, 0, 0, 1, 0, -1, 0, 1, 0, -1, 0, 0, 0, -1, 0, 1, 0, -1, 0, 1, 0, 0, 0, 1, 0, -1, 0, 1, 0, -1, 0, 0, 0, -1, 0, 1, 0, -1, 0, 1, 0, 0, 0, 1, 0, -1, 0, 1, 0, -1, 0, 0, 0, -1, 0, 1, 0, -1, 0, 1, 0, 0, 0, 1, 0, -1, 0, 1, 0, -1, 0, 0, 0, -1, 0, 1, 0, -1, 0, 1, 0, 0, 0, 1, 0, -1, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Michael Somos, Rational Function Multiplicative Coefficients Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, -1). FORMULA a(n) is multiplicative with a(2^e) = a(5^e) = 0^e, a(p^e) = 1 if p == 1 (mod 4) and p>5, a(p^e) = (-1)^e if p == 3 (mod 4). Euler transform of length 20 sequence [ 0, -1, 0, 0, 0, -1, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1]. G.f.: x * (1 - x^2) * (1 - x^6) / (1 + x^10) = x / (1 + x^2) - x^5 / (1 + x^10). a(n + 20) = -a(-n) = a(n). a(2*n) = a(5*n) = 0. Dirichlet convolution with A000012 is A053694 offset 1. EXAMPLE x - x^3 - x^7 + x^9 - x^11 + x^13 + x^17 - x^19 + x^21 - x^23 - x^27 + ... MATHEMATICA f[n_] := KroneckerSymbol[-100, n]; Array[f, 100] (* Robert G. Wilson v *) PROG (PARI) {a(n) = kronecker( -100, n)} (PARI) {a(n) = (n%2) * (-1) ^ (n\10) * kronecker( 5, n)} (PARI) {a(n) = sign(n) * polcoeff( x * (1 - x^2) * (1 - x^6) / (1 + x^10) + x * O(x^abs(n)), abs(n))} (PARI) {a(n) = local( A, p, e); if( n==0, 0, A = factor( abs(n)); sign(n) * prod( k=1, matsize( A)[1], if(p = A[k, 1], e = A[k, 2]; if( p==2 | p==5, 0, if( p%4==1, 1, (-1)^e )))))} CROSSREFS Cf. A053694. Sequence in context: A015029 A014789 A014669 * A266282 A228747 A285162 Adjacent sequences:  A185273 A185274 A185275 * A185277 A185278 A185279 KEYWORD sign,mult AUTHOR Michael Somos, Feb 19 2011 STATUS approved

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Last modified May 7 00:49 EDT 2021. Contains 343616 sequences. (Running on oeis4.)