A082855 a(0)=0, a(1)=1, a(n) = A014137(A081288(n-1)-1).

0, 1, 2, 4, 4, 4, 9, 9, 9, 9, 9, 9, 9, 9, 9, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65

Offset: 0

Author

Antti Karttunen, Apr 17 2003

Keywords

• nonn

Comments

After n>0, A014137(n) occurs A000245(n) times.

Crossrefs

Cf. A081289, A082852. A081291(n) = n+A082855(n+1) for n>0.

Programs

PARI

A014137(n) = sum(k=0, n, binomial(2*k, k)/(k+1););
A081288(n) = my(i=0); while(binomial(2*i, i)/(i+1) <= n, i++); i;
a(n) = if (n<=1, n, A014137(A081288(n-1)-1)); \\ Michel Marcus, Apr 28 2020

Scheme

(define (A082855 n) (if (< n 2) n (A014137 (-1+ (A081288 (-1+ n))))))