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A120140
a(n) = 13 + floor(Sum_{j=1..n-1} a(j)/2).
3
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
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
KEYWORD
nonn
AUTHOR
Graeme McRae, Jun 10 2006
STATUS
approved