id:A109961 - OEIS Search Results

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Expansion of (1-3x+3x^2-x^3)/(1-4x+5x^2-4x^3+x^4).

+0
4

1, 1, 2, 6, 17, 45, 117, 305, 798, 2090, 5473, 14329, 37513, 98209, 257114, 673134, 1762289, 4613733, 12078909, 31622993, 82790070, 216747218, 567451585, 1485607537, 3889371025, 10182505537, 26658145586, 69791931222, 182717648081 (list; graph; listen)

	OFFSET	`0,3`
	COMMENT	`Diagonal sums of number triangle A109960.`
	FORMULA	`G.f.: (1-x)^3/(1-4x+5x^2-4x^3+x^4); a(n)=sum{k=0..floor(n/2), binomial(n+2k, 4k)}.`
	CROSSREFS	`Sequence in context: A000996 A020963 A065068 this_sequence A005592 A102403 A032638` `Adjacent sequences: A109958 A109959 A109960 this_sequence A109962 A109963 A109964`
	KEYWORD	`easy,nonn`
	AUTHOR	`Paul Barry (pbarry(AT)wit.ie), Jul 06 2005`

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

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