id:A154949 - OEIS Search Results

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Diagonal sums of Riordan array A154948.

+0
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1, 1, 3, 5, 10, 18, 34, 62, 115, 211, 389, 715, 1316, 2420, 4452, 8188, 15061, 27701, 50951, 93713, 172366, 317030, 583110, 1072506, 1972647, 3628263, 6673417, 12274327, 22576008, 41523752, 76374088, 140473848, 258371689, 475219625 (list; graph; listen)

	OFFSET	`0,3`
	FORMULA	`G.f.: 1/((1-x^2)(1-x-x^2-x^3));` `a(n)=sum{k=0..floor(n/2), sum{j=0..n-k+1, C(n-k+1-j,k+1)C(k-1,j)}}.`
	CROSSREFS	`Sequence in context: A054179 A010049 A094986 this_sequence A107232 A134522 A001445` `Adjacent sequences: A154946 A154947 A154948 this_sequence A154950 A154951 A154952`
	KEYWORD	`easy,nonn`
	AUTHOR	`Paul Barry (pbarry(AT)wit.ie), Jan 17 2009`

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

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