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A137856
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Row sums of triangle A137855.
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2
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1, 2, 4, 8, 17, 39, 97, 261, 756, 2343, 7722, 26917, 98789, 380360, 1531698, 6434385, 28130890, 127729730, 601196428, 2928369917, 14738842361, 76547694741, 409718539681, 2257459567236, 12789959138943, 74439150889080, 444647798089245, 2723583835351855
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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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a(n) = Sum_{k=1..n} Sum_{j=1..n-k+1} Stirling2(k, j). - Andrew Howroyd, Aug 09 2018
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EXAMPLE
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a(5) = 17 = sum of row 5 terms of triangle A137855: (1 + 2 + 5 + 8 + 1).
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PROG
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(PARI) a(n)={sum(k=1, n, sum(j=1, n-k+1, stirling(k, j, 2)))} \\ Andrew Howroyd, Aug 09 2018
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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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STATUS
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approved
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