A097789 a(n)=4a(n-1)+C(n+4,4),n>0, a(0)=1.

1, 9, 51, 239, 1026, 4230, 17130, 68850, 275895, 1104295, 4418181, 17674089, 70698176, 282795084, 1131183396, 4524737460, 18098954685, 72395824725, 289583306215, 1158333233715, 4633332945486, 18533331794594, 74133327193326

Offset: 0

Author

Paul Barry, Aug 24 2004

Keywords

• easy
• nonn

Comments

Partial sums of A097788.

Links

• Index entries for linear recurrences with constant coefficients, signature (9,-30,50,-45,21,-4).

Formula

G.f. : 1/((1-4x)(1-x)^5); a(n)=4^(n + 5)/243-(27n^4+414n^3+2385n^2+6198n+6248)/1944; a(n)=sum{k=0..n, binomial(n+5, k+5)3^k}.