A033490 - OEIS

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A033490

a(1) = 1, a(2) = 2, otherwise a(n) = 2a(n-1) + a(floor(n/2)).

1, 2, 5, 12, 26, 57, 119, 250, 512, 1050, 2126, 4309, 8675, 17469, 35057, 70364, 140978, 282468, 565448, 1131946, 2264942, 4532010, 9066146, 18136601, 36277511, 72563697, 145136069, 290289607, 580596683 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	MAPLE	`A033490 := proc(n) option remember; if n <= 2 then n else A033490(n-1)+A033490(round(2*(n-1)/2))+A033490(round((n-1)/2)); fi; end;`
	PROG	`(PARI) a=vector(99, i, i); for(n=3, #a, a[n]=2*a[n-1]+a[n\2]); a \\ Charles R Greathouse IV, Nov 29 2011`
	CROSSREFS	`Sequence in context: A116726 A125180 A073778 * A116716 A128812 A078410` `Adjacent sequences: A033487 A033488 A033489 * A033491 A033492 A033493`
	KEYWORD	`nonn,easy`
	AUTHOR	`N. J. A. Sloane (njas(AT)research.att.com).`

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Last modified February 15 21:56 EST 2012. Contains 205860 sequences.