A055990 - OEIS

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A055990

a(n) is its own 4th difference.

1, 4, 14, 50, 181, 657, 2385, 8657, 31422, 114051, 413966, 1502555, 5453761, 19795288, 71850128, 260791401, 946583628, 3435774958, 12470688498, 45264335853, 164294064481, 596331286321, 2164478699633, 7856317702310 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,2`
	FORMULA	`a(n)=5a(n-1)-6a(n-2)+4a(n-3)-a(n-4) =a(n-1)+A055989(n) =A055991(n)-A055991(n-1) =A055988(n+1)-2*A055988(n)+A055988(n-1)`
	CROSSREFS	`Cf. A055988, A055989, A055991 for the other differences of a(n). See A000079, A001906, A052529 for examples of sequences which are respectively their own first, second and third differences.` `Sequence in context: A153367 A047008 A047065 * A087945 A051924 A076024` `Adjacent sequences: A055987 A055988 A055989 * A055991 A055992 A055993`
	KEYWORD	`nonn`
	AUTHOR	`Henry Bottomley (se16(AT)btinternet.com), Jun 02 2000`
	EXTENSIONS	`More terms from James A. Sellers (sellersj(AT)math.psu.edu), Jun 05 2000`

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Last modified February 16 20:01 EST 2012. Contains 205955 sequences.