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A126982 Expansion of 1/(1+3*x*c(x)), c(x) the g.f. of Catalan numbers A000108. 6
1, -3, 6, -15, 30, -78, 144, -423, 630, -2490, 1956, -16998, -5844, -142860, -235740, -1475415, -3951450, -17627490, -57571740, -228692610, -810889020, -3098590020, -11377872720, -43011709110, -160518364740, -606261789828 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Hankel transform is (-3)^n.

Catalan transform of the sequence (-1)^n*A000244(n). [From R. J. Mathar, Nov 11 2008]

LINKS

Table of n, a(n) for n=0..25.

FORMULA

a(n)=Sum_{k, 0<=k<=n}A039599(n,k)*(-4)^k.

CROSSREFS

Sequence in context: A183038 A141023 A242172 * A256281 A034739 A276670

Adjacent sequences:  A126979 A126980 A126981 * A126983 A126984 A126985

KEYWORD

sign

AUTHOR

Philippe Deléham, Mar 21 2007

EXTENSIONS

Extended by R. J. Mathar, Nov 11 2008

STATUS

approved

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Last modified February 21 16:28 EST 2018. Contains 299414 sequences. (Running on oeis4.)