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A049126 Revert transform of ((x - 1)(3x - 1))/(1 - 3x + x^3). 0
1, 1, 2, 6, 22, 90, 393, 1789, 8378, 40050, 194492, 956448, 4752519, 23822571, 120315345, 611644737, 3127389106, 16072642890, 82981119252, 430187414196, 2238469102212, 11687227631892, 61208286479382, 321465732705594 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..24.

Index entries for reversions of series

FORMULA

Revert transform of A122100 offset 1. - Michael Somos, May 11 2012

EXAMPLE

G.f. = x + x^2 + 2*x^3 + 6*x^4 + 22*x^5 + 90*x^6 + 393*x^7 + 1789*x^8 + ...

PROG

(PARI) {a(n) = if( n<1, 0, polcoeff( serreverse(x * (1 - 4*x + 3*x^2) / (1 - 3*x + x^3) + x * O(x^n)), n))}; /* Michael Somos, May 11 2012 */

CROSSREFS

Cf. A122100.

Sequence in context: A150270 A049136 A165523 * A049134 A086456 A155069

Adjacent sequences:  A049123 A049124 A049125 * A049127 A049128 A049129

KEYWORD

nonn

AUTHOR

Olivier Gérard

STATUS

approved

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Last modified December 10 04:15 EST 2019. Contains 329885 sequences. (Running on oeis4.)