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A180166
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Row sums of triangle A180165.
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2
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1, 3, 7, 18, 51, 161, 560, 2123, 8691, 38142, 178407, 885041, 4636948, 25564727, 147848651, 894448186, 5646589363, 37115577265, 253517232120, 1796241061843, 13180234725987, 100009217354694, 783656713398383, 6333420109604593, 52732283687195340, 451831859926030943
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OFFSET
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1,2
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LINKS
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FORMULA
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G.f.: Sum_{k>=1} x^k*(1 + x)/(1 - k*x - k*x^2). - Andrew Howroyd, Apr 13 2021
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EXAMPLE
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a(5) = 151 = sum of row 5 terms of triangle A180165: (1 + 5 + 15 + 22 + 8).
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PROG
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(PARI) seq(n)={Vec(sum(k=1, n, x^k*(1+x)/(1-k*x-k*x^2) + O(x*x^n)))} \\ Andrew Howroyd, Apr 13 2021
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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a(8) and a(11) corrected and a(14) and beyond from Andrew Howroyd, Apr 13 2021
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STATUS
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approved
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