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A336513

a(n) = Sum_{i=1..n} Product_{j=(i-1)*n+1..i*n} j.

1, 14, 630, 57264, 8626800, 1940869440, 609372212400, 254507088084480, 136432540607489280, 91303132805512992000, 74605774050426543724800, 73097485140038735163110400, 84588938888439008795675904000, 114144070365165930162064530739200, 177648727691418999798103189989120000

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Seiichi Manyama, Table of n, a(n) for n = 1..214

FORMULA

a(n) = n! * A096131(n) = n! * Sum_{k=1..n} binomial(k*n, n).

EXAMPLE

a(2) = 1*2 + 3*4 = 14.

a(3) = 1*2*3 + 4*5*6 + 7*8*9 = 630.

a(4) = 1*2*3*4 + 5*6*7*8 + 9*10*11*12 + 13*14*15*16 = 57264.

MATHEMATICA