A216628 - OEIS

A216628

a(n) = A163085(n)/n!.

1, 1, 1, 2, 3, 18, 60, 1200, 10500, 735000, 18522000, 4667544000, 359400888000, 332086420512000, 81408613942656000, 279394363051195392000, 224737840779305293440000, 2892376010829659126572800000, 7812628980363223707442752000000, 379850021025259936655866602240000000

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

OFFSET

0,4

LINKS

Table of n, a(n) for n=0..19.

PROG

(Sage)

def A216628(n):

swing = lambda n: factorial(n)/factorial(n//2)^2

A163085 = lambda n: mul(swing(i) for i in (0..n))

return A163085(n)/factorial(n)

[A216628(n) for n in (0..19)]