A055863 Fifth column of triangle A055858.

0, 0, 0, 0, 320, 4500, 74088, 1404928, 30233088, 729000000, 19487171000, 572305637376, 18324574916544, 635492476982272, 23734930078125000, 949978046398464000, 40569151622782717952, 1841458074930764070912

Offset: 0

Author

Wolfdieter Lang Jun 20 2000

Keywords

• nonn
• easy

Crossrefs

a(n)=A055858(n, 4). Cf. A000312, A000169, A055860-A055862.

Formula

a(i)=0, i=0..3; a(n)= (n^3)*(n+1)^(n-3), n >= 4.

E.g.f.: -x*(3+16*x+54*x^2)/12+(W(-x)^2)*(3-7*W(-x)+2*W(-x)^2)/ (12*(1+W(-x))*x), W(x) principal branch of Lambert's function.