A100009 a(1) = 2; for n >= 2, a(n) = f(a(n-1)) where f(n) = n*(n+1)*(n+2)*(n+3)/24.

2, 5, 70, 1088430, 58478088289964410654020

Offset: 1

Author

Jonathan Vos Post, Nov 16 2004

Keywords

• easy
• nonn
• less

Comments

The next term has 90 digits.

Crossrefs

Cf. A000332.

Programs

Mathematica

NestList[(6 #+11 #^2+6 #^3+#^4)/24&,2,6] (* Harvey P. Dale, Dec 14 2024 *)