id:A124280 - OEIS Search Results

Search: id:A124280

Displaying 1-1 of 1 results found.

page 1

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

+0
3

1, 1, 2, 2, 4, 5, 9, 12, 20, 28, 45, 65, 102, 150, 232, 345, 529, 792, 1208, 1816, 2761, 4161, 6314, 9530, 14444, 21821, 33049, 49956, 75628, 114356, 173077, 261761, 396110, 599150, 906576, 1371377, 2074913, 3138864 (list; graph; listen)

	OFFSET	`0,3`
	COMMENT	`Diagonal sums of number triangle A124279.`
	FORMULA	`a(n)=sum{k=0..floor(n/2), sum{j=0..n-2k, C(j,n-2k-j)C(k,n-2k-j)}}`
	CROSSREFS	`Sequence in context: A144118 A089935 A038000 this_sequence A088518 A001224 A102526` `Adjacent sequences: A124277 A124278 A124279 this_sequence A124281 A124282 A124283`
	KEYWORD	`easy,nonn`
	AUTHOR	`Paul Barry (pbarry(AT)wit.ie), Oct 24 2006`

page 1

Search completed in 0.002 seconds

Last modified December 6 13:45 EST 2009. Contains 170429 sequences.

AT&T Labs Research