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A027793 a(n) = 28*(n+1)*C(n+3,8)/3. 0
56, 588, 3360, 13860, 46200, 132132, 336336, 780780, 1681680, 3403400, 6534528, 11992344, 21162960, 36085560, 59690400, 96101544, 151016712, 232178100, 349949600, 518017500, 754233480, 1081620540, 1529564400 (list; graph; refs; listen; history; text; internal format)
OFFSET

5,1

LINKS

Table of n, a(n) for n=5..27.

Index entries for linear recurrences with constant coefficients, signature (10,-45,120,-210,252,-210,120,-45,10,-1)

FORMULA

Number of 12-subsequences of [ 1, n ] with just 3 contiguous pairs; g.f. 28*(2+x)*x^5/(1-x)^10.

a(n) = C(n+1, 6)*C(n+3, 3). - Zerinvary Lajos, May 13 2005, corrected by R. J. Mathar, Feb 10 2016

CROSSREFS

Sequence in context: A219712 A244429 A005931 * A244945 A055747 A234106

Adjacent sequences:  A027790 A027791 A027792 * A027794 A027795 A027796

KEYWORD

nonn

AUTHOR

thi ngoc dinh (via R. K. Guy)

STATUS

approved

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Last modified March 28 05:38 EDT 2020. Contains 333073 sequences. (Running on oeis4.)