A090413 - OEIS

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A090413

A Chebyshev transform of 3^n.

1, 3, 8, 21, 56, 150, 400, 1065, 2840, 7578, 20208, 53874, 143664, 383148, 1021728, 2724465, 7265240, 19374450, 51665200, 137772246, 367392656, 979719348, 2612584928, 6966873546, 18578329456, 49542281220, 132112749920 (list; graph; refs; listen; history; internal format)

	OFFSET	`0,2`
	FORMULA	`G.f.: c(-x^2)/(1-3xc(-x^2)), c(x) g.f. of Catalan numbers A000108; a(n)=sum{k=0..n, (k+1)C(n, n/2-k/2)(-1)^(n/2-k/2)(1+(-1)^(n+k))3^k/(n+k+2)}.`
	CROSSREFS	`Sequence in context: A001906 A072632 A001671 * A128105 A085560 A094374` `Adjacent sequences: A090410 A090411 A090412 * A090414 A090415 A090416`
	KEYWORD	`easy,nonn`
	AUTHOR	`Paul Barry (pbarry(AT)wit.ie), Dec 05 2003`

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Last modified February 14 08:58 EST 2012. Contains 205614 sequences.