A120144 a(n) = 19 + floor( Sum_{j=1..n-1} a(j) / 2 ).

19, 28, 42, 63, 95, 142, 213, 320, 480, 720, 1080, 1620, 2430, 3645, 5467, 8201, 12301, 18452, 27678, 41517, 62275, 93413, 140119, 210179, 315268, 472902, 709353, 1064030, 1596045, 2394067, 3591101, 5386651, 8079977, 12119965, 18179948

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. A073941, A072493, A112088, A120134 - A120143, A120145 - A120209.

Programs

Mathematica

a[n_]:= a[n]= 19 +Quotient[Sum[a[k], {k,n-1}], 2];
Table[a[n], {n,60}] (* G. C. Greubel, May 14 2023 *)

SageMath

@CachedFunction
def A120144(n): return 19 + sum(A120144(k) for k in range(1,n))//2
[A120144(n) for n in range(1,61)] # G. C. Greubel, May 14 2023