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A120156
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a(n) = 11 + floor((2 + Sum_{j=1..n-1} a(j))/3).
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1
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11, 15, 20, 27, 36, 48, 64, 85, 113, 151, 201, 268, 358, 477, 636, 848, 1131, 1508, 2010, 2680, 3574, 4765, 6353, 8471, 11295, 15060, 20080, 26773, 35697, 47596, 63462, 84616, 112821, 150428, 200571, 267428, 356570, 475427, 633903, 845204
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OFFSET
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1,1
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LINKS
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MATHEMATICA
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PROG
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(Magma)
function f(n, a, b)
t:=0;
for k in [1..n-1] do
t+:= a+Floor((b+t)/3);
end for;
return t;
end function;
g:= func< n, a, b | f(n+1, a, b)-f(n, a, b) >;
(SageMath)
@CachedFunction
def A120156(n): return 11 +(2+sum(A120156(k) for k in range(1, n)))//3
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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