id:A025248 - OEIS Search Results

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a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ...+ a(n-3)*a(3) for n >= 4.

+0
2

1, 0, 2, 2, 2, 6, 14, 26, 58, 142, 326, 754, 1826, 4438, 10750, 26378, 65354, 162334, 405046, 1016546, 2561074, 6472550, 16415086, 41761786, 106526810, 272411054, 698275622, 1793763282, 4617047618, 11906277750, 30757124830, 79582907370, 206231537770 (list; graph; listen)

	OFFSET	`1,3`
	FORMULA	`G.f.: (1+x-sqrt(1-2x+x^2-8x^3))/2 - Michael Somos, Jun 08, 2000.`
	PROGRAM	`(PARI) a(n)=polcoeff((x-sqrt(1-2x+x^2-8x^3+x*O(x^n)))/2, n)`
	CROSSREFS	`Sequence in context: A032306 A058756 A007039 this_sequence A098920 A129365 A021453` `Adjacent sequences: A025245 A025246 A025247 this_sequence A025249 A025250 A025251`
	KEYWORD	`nonn`
	AUTHOR	`Clark Kimberling (ck6(AT)evansville.edu)`

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Last modified September 7 15:23 EDT 2008. Contains 143483 sequences.

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