A120142 a(n) = 16 + floor(Sum_{j=1..n-1} a(j)/2).

16, 24, 36, 54, 81, 121, 182, 273, 409, 614, 921, 1381, 2072, 3108, 4662, 6993, 10489, 15734, 23601, 35401, 53102, 79653, 119479, 179219, 268828, 403242, 604863, 907295, 1360942, 2041413, 3062120, 4593180, 6889770, 10334655, 15501982

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 - A120141, A120143 - A120209.

Programs

Mathematica

Nest[Append[#,16+Floor[Total[#]/2]]&,{16},40]  (* Harvey P. Dale, Apr 20 2011 *)

SageMath

@CachedFunction
def A120142(n): return 16 + (sum(A120142(k) for k in range(1,n)))//2
[A120142(n) for n in range(1,60)] # G. C. Greubel, May 11 2023