A120149 a(n) = 2 + floor((1 + Sum_{j=1..n-1} a(j))/3).

2, 3, 4, 5, 7, 9, 12, 16, 21, 28, 38, 50, 67, 89, 119, 159, 212, 282, 376, 502, 669, 892, 1189, 1586, 2114, 2819, 3759, 5012, 6682, 8910, 11880, 15840, 21120, 28160, 37546, 50062, 66749, 88999, 118665, 158220, 210960, 281280, 375040, 500053, 666738

Offset: 1

Author

Graeme McRae, Jun 10 2006

Keywords

• nonn

Links

• G. C. Greubel, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A072493, A073941, A112088.

Programs

Mathematica

f[s_] := Append[s, Floor[(7 + Plus @@ s)/3]]; Nest[f, {2}, 44] (*  Robert G. Wilson v, Jul 08 2006 *)

SageMath

@CachedFunction
def A120149(n): return 2 + (1+sum(A120149(k) for k in range(1,n)))//3
[A120149(n) for n in range(1, 61)] # G. C. Greubel, Jun 04 2023

Extensions

More terms from Robert G. Wilson v, Jul 08 2006