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A273218 G.f. A(x) satisfies: A(x) = A(x^2 - x^3)/x. 2
1, -1, -1, 2, -2, 3, -1, -7, 10, 2, -15, 2, 34, -51, 17, 73, -218, 323, -135, -467, 1139, -1279, 430, 1587, -4274, 5798, -3249, -5664, 19061, -26208, 9976, 34430, -77516, 62473, 45193, -186383, 173814, 186306, -747220, 754744, 678009, -3221980, 4339761, -491173, -8988984, 17693649, -12889827, -13658278, 48487713, -52398012, -8596387, 107984036, -138251503, -10832334, 290867000, -398695112, -38910128, 956034308, -1433632474, 169017884 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Equals the series reversion of the g.f. of A273162.

LINKS

Paul D. Hanna, Table of n, a(n) for n = 1..1030

EXAMPLE

G.f.: A(x) = x - x^2 - x^3 + 2*x^4 - 2*x^5 + 3*x^6 - x^7 - 7*x^8 + 10*x^9 + 2*x^10 - 15*x^11 + 2*x^12 + 34*x^13 - 51*x^14 + 17*x^15 + 73*x^16 - 218*x^17 +...

such that A(x) = A(x^2 - x^3)/x.

RELATED SERIES.

Let B(x) be the series reversion of g.f. A(x), so that B(A(x)) = x, then

B(x) = x + x^2 + 3*x^3 + 8*x^4 + 28*x^5 + 95*x^6 + 351*x^7 + 1309*x^8 + 5056*x^9 + 19787*x^10 + 78847*x^11 +...+ A273162(n)*x^n +...

such that B(x*A(x)) = x^2 - x^3.

PROG

(PARI) {a(n) = my(A=x); for(i=1, #binary(n)+1, A = subst(A, x, x^2 - x^3 + x^2*O(x^n))/x); polcoeff(A, n) }

for(n=1, 60, print1(a(n), ", "))

CROSSREFS

Cf. A273162.

Sequence in context: A219865 A016539 A220349 * A173160 A022461 A306821

Adjacent sequences:  A273215 A273216 A273217 * A273219 A273220 A273221

KEYWORD

sign

AUTHOR

Paul D. Hanna, May 17 2016

STATUS

approved

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Last modified October 19 11:26 EDT 2019. Contains 328216 sequences. (Running on oeis4.)