A109963 Diagonal sums of number triangle A109962.

1, -1, 5, -27, 171, -1178, 8582, -65029, 507317, -4047608, 32874104, -270893586, 2259210814, -19032956491, 161735556091, -1384662302187, 11931865642979, -103409449621325, 900778907303037, -7882176975668156, 69253864680597564, -610717827031587856

Offset: 0

Author

Paul Barry, Jul 06 2005

Keywords

• easy
• sign

Formula

G.f.: g/(1-f) where f/(1-f)^4=x and g=1/(1-f); a(n)=(-1)^n*sum{k=0..floor(n/2), ((4k+1)/(3n-2k+1))*binomial(4n-4k, n-2k)}.