id:A026126 - OEIS Search Results

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a(n) = number of (s(0),s(1),...,s(n)) such that every s(i) is a nonnegative integer, s(0) = 1, s(n) = 5, |s(1) - s(0)| = 1, |s(i) - s(i-1)| <= 1 for i >= 2. Also a(n) = T(n,n-4), where T is the array in A026120.

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1, 4, 16, 56, 188, 608, 1922, 5972, 18326, 55704, 168090, 504348, 1506531, 4484208, 13309572, 39414568, 116508361, 343890196, 1013840836, 2986129168, 8788591801, 25850576024, 76000747820, 223361900840, 656270632875, 1927845012756 (list; graph; listen)

	OFFSET	`4,2`
	FORMULA	`G.f.: z^4(1-z)^2M^6, with M the g.f. of the Motzkin numbers (A001006).` `Second differences of A005325.`
	CROSSREFS	`Sequence in context: A127393 A073388 A109634 this_sequence A026155 A025182 A057585` `Adjacent sequences: A026123 A026124 A026125 this_sequence A026127 A026128 A026129`
	KEYWORD	`nonn`
	AUTHOR	`Clark Kimberling (ck6(AT)evansville.edu)`
	EXTENSIONS	`Corrected by R. Stephan, Apr 06 2004`

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Last modified December 4 12:27 EST 2008. Contains 151280 sequences.

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