A136591 Column 1 of triangle A136590.

1, 1, -4, 6, 24, -240, 720, 5040, -80640, 362880, 3628800, -79833600, 479001600, 6227020800, -174356582400, 1307674368000, 20922789888000, -711374856192000, 6402373705728000, 121645100408832000, -4865804016353280000, 51090942171709440000

Offset: 1

Author

Paul D. Hanna, Jan 10 2008

Keywords

• sign

Crossrefs

Cf. A136590, A136592, A136593, A136594; A061347.

Programs

PARI

{a(n) = n!*polcoeff( log(1+x+x^2 +x*O(x^(n+1))),n)}
for(n=1,30,print1(a(n),", "))

Formula

E.g.f.: log(1 + x + x^2).

a(n) = n!*A061347(n) for n>=1.