A123490 - OEIS

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A123490

Triangle whose k-th column satisfies a(n)=(k+3)*a(n-1)-(k+2)*a(n-2).

1, 2, 1, 4, 2, 1, 8, 5, 2, 1, 16, 14, 6, 2, 1, 32, 41, 22, 7, 2, 1, 64, 122, 86, 32, 8, 2, 1, 128, 365, 342, 157, 44, 9, 2, 1, 256, 1094, 1366, 782, 260, 58, 10, 2, 1 (list; table; graph; refs; listen; history; internal format)

	OFFSET	`0,2`
	COMMENTS	`Column k has g.f. x^k(1-x(1+k))/((1-x)(1-x(2+k))). Row sums are A103439. Columns include A000079,A007051,A047849,A047850,A047851. Diagonal sums are A123491.`
	FORMULA	`Number triangle T(n,k)=[k<=n]*((k+2)^(n-k)+k)/(k+1)`
	EXAMPLE	`Triangle begins` `1,` `2, 1,` `4, 2, 1,` `8, 5, 2, 1,` `16, 14, 6, 2, 1,` `32, 41, 22, 7, 2, 1,` `64, 122, 86, 32, 8, 2, 1,` `128, 365, 342, 157, 44, 9, 2, 1,` `256, 1094, 1366, 782, 260, 58, 10, 2, 1,` `512, 3281, 5462, 3907, 1556, 401, 74, 11, 2, 1,` `1024, 9842, 21846, 19532, 9332, 2802, 586, 92, 12, 2, 1`
	CROSSREFS	`Cf. A047848.` `Sequence in context: A180870 A054453 A109433 * A157028 A060637 A123486` `Adjacent sequences: A123487 A123488 A123489 * A123491 A123492 A123493`
	KEYWORD	`easy,nonn,tabl`
	AUTHOR	`Paul Barry (pbarry(AT)wit.ie), Oct 01 2006`

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Last modified February 16 02:30 EST 2012. Contains 205860 sequences.