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A022997 Numerator of n*(n-2)*(2*n-1)/(2*(n-1)). 0
0, 15, 28, 135, 132, 455, 360, 1071, 760, 2079, 1380, 3575, 2268, 5655, 3472, 8415, 5040, 11951, 7020, 16359, 9460, 21735, 12408, 28175, 15912, 35775, 20020, 44631, 24780, 54839, 30240, 66495, 36448 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,2

LINKS

Table of n, a(n) for n=2..34.

Index entries for linear recurrences with constant coefficients, signature (0, 4, 0, -6, 0, 4, 0, -1).

FORMULA

G.f. x^3(x^6+5x^4+20x^3+75x^2+28x+15)/(x-1)^4/(x+1)^4. - Ralf Stephan, Sep 03 2003

CROSSREFS

Sequence in context: A223442 A121594 A163286 * A256876 A051121 A001356

Adjacent sequences:  A022994 A022995 A022996 * A022998 A022999 A023000

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified April 16 12:45 EDT 2021. Contains 343037 sequences. (Running on oeis4.)