A358431 a(0) = 1; a(n+1) = 1 if a(n) > n, otherwise a(n+1) = a(n) + a(a(n)).

1, 1, 2, 4, 1, 2, 4, 5, 7, 12, 1, 2, 4, 5, 7, 12, 16, 32, 1, 2, 4, 5, 7, 12, 16, 32, 1, 2, 4, 5, 7, 12, 16, 32, 48, 1, 2, 4, 5, 7, 12, 16, 32, 48, 1, 2, 4, 5, 7, 12, 16, 32, 48, 55, 1, 2, 4, 5, 7, 12, 16, 32, 48, 55, 57, 62, 110, 1, 2, 4, 5, 7, 12, 16, 32, 48, 55, 57, 62, 110

Offset: 0

Author

Aidan Clarke, Nov 15 2022

Keywords

• nonn

Crossrefs

Cf. A062039.

Programs

Mathematica

a[0] = 1; a[n_] := a[n] = If[a[n - 1] > n - 1, 1, a[n - 1] + a[a[n - 1]]]; Array[a, 80, 0] (* Amiram Eldar, Dec 06 2022 *)

Python

from functools import cache
@cache
def a(n): return 1 if n==0 else (1 if a(n-1) > n-1 else a(n-1) + a(a(n-1)))
print([a(n) for n in range(76)]) # Michael S. Branicky, Nov 15 2022