A120140 a(n) = 13 + floor(Sum_{j=1..n-1} a(j)/2).

13, 19, 29, 43, 65, 97, 146, 219, 328, 492, 738, 1107, 1661, 2491, 3737, 5605, 8408, 12612, 18918, 28377, 42565, 63848, 95772, 143658, 215487, 323230, 484845, 727268, 1090902, 1636353, 2454529, 3681794, 5522691, 8284036, 12426054, 18639081

Offset

1,1

Links

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

Mathematica

a[n_]:= a[n]= 13 +Quotient[Sum[a[k], {k, n-1}], 2];
Table[a[n], {n, 60}] (* G. C. Greubel, May 11 2023 *)

Prog

(SageMath)
@CachedFunction
def A120140(n): return 13 + sum(A120140(k) for k in range(1, n))//2
[A120140(n) for n in range(1, 60)] # G. C. Greubel, May 11 2023

Crossrefs

Cf. A073941, A072493, A112088, A120134 - A120139, A120141 - A120209.

Sequence in context: A089391 A038954 A005106 * A101849 A141562 A353205

Adjacent sequences: A120137 A120138 A120139 * A120141 A120142 A120143

Keyword

nonn

Author

Graeme McRae, Jun 10 2006

Status

approved