A093887 a(n) = A093886(n)/(1!*2!*3!*...*n!).

1, 1, 2, 140, 105, 840840, 51051, 79755701025, 143400750442950, 122535439350874224675, 46705681584242830001657805, 65358008635496174751045143339993779875

Offset

1,3

Links

Table of n, a(n) for n=1..12.

Example

a(4) = 140 = 8! /(1!*2!*3!*4!) = 40320/288.

Maple

a:=proc(n) local A, k: A:={}: for k from 1 to n*(n+1)/2 do if type(k!/product(j!, j=1..n), integer)=true then A:=A union {k} else A:=A fi od: A[1]!/product(i!, i=1..n); end: seq(a(n), n=1..14); # not necessarily the best Maple program # Emeric Deutsch, Feb 03 2006

Crossrefs

Cf. A093886.

Sequence in context: A094482 A265176 A101232 * A152005 A140898 A220513

Adjacent sequences: A093884 A093885 A093886 * A093888 A093889 A093890

Keyword

nonn

Author

Amarnath Murthy, Apr 23 2004

Extensions

More terms from Emeric Deutsch, Feb 03 2006

Status

approved