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A101912 G.f. satisfies: A(x) = 1/(1 + x*A(x^2)) and also the continued fraction: 1+x*A(x^3) = [1;1/x,1/x^2,1/x^4,1/x^8,...,1/x^(2^(n-1)),...]. +0
7
1, -1, 1, 0, -1, 1, 0, -2, 3, -1, -3, 6, -4, -4, 12, -10, -5, 23, -25, -2, 43, -57, 12, 74, -124, 56, 120, -258, 172, 170, -516, 454, 187, -989, 1095, 40, -1811, 2487, -604, -3128, 5375, -2567, -4991, 11140, -7704, -6976, 22164, -20062, -7220, 42288, -48020, -36, 76928, -108334, 29476, 131898, -233020, 117166 (list; graph; listen)
OFFSET

0,8

COMMENT

Sequence appears to have a rational g.f. - Ralf Stephan, May 17 2007

PROGRAM

(PARI) {a(n)=local(A); A=1-x; for(i=1, n\2+1, A=1/(1+x*subst(A, x, x^2)+x*O(x^n))); polcoeff(A, n, x)} (PARI) {a(n)=local(M=contfracpnqn(concat(1, vector(#binary(n)+1, n, 1/x^(2^(n-1)))))); polcoeff(M[1, 1]/M[2, 1]+x*O(x^(3*n+1)), 3*n+1)}

CROSSREFS

Cf. A101913-A101918.

Sequence in context: A153861 A118981 A117938 this_sequence A111808 A081422 A027555

Adjacent sequences: A101909 A101910 A101911 this_sequence A101913 A101914 A101915

KEYWORD

sign

AUTHOR

Paul D. Hanna (pauldhanna(AT)juno.com), Dec 20 2004

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.


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