id:A098461 - OEIS Search Results

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E.g.f.: 1/sqrt(1-2x-3x^2).

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1, 1, 6, 42, 456, 6120, 101520, 1980720, 44634240, 1139080320, 32488646400, 1023985670400, 35345049062400, 1325988036172800, 53721616851302400, 2337607853957376000, 108727934847307776000, 5383304681800421376000 (list; graph; listen)

	OFFSET	`0,3`
	FORMULA	`a(n)=(n!/2^n)A098453(n); a(n)=(n!/2^n)sum{k=0..floor(n/2), Binomial(n, k)Binomial(2(n-k), n)3^k}.`
	CROSSREFS	`Cf. A012244, A098460.` `Sequence in context: A052589 A074107 A052608 this_sequence A034662 A074651 A139223` `Adjacent sequences: A098458 A098459 A098460 this_sequence A098462 A098463 A098464`
	KEYWORD	`easy,nonn`
	AUTHOR	`Paul Barry (pbarry(AT)wit.ie), Sep 08 2004`

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Last modified December 17 19:39 EST 2009. Contains 170821 sequences.

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