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A147291
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a(n) = Sum_{k=1..n^2-1} binomial(2k,k).
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1
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0, 28, 17576, 209295260, 43308802158650, 150315393336149895056, 8610524734277600186228691452, 8068213695203463278728832778415607708, 122985780058082302876789680971972469134558550878, 30386103720799858392019761983012781659021124133753353112778
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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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MATHEMATICA
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Table[Sum[Binomial[2*k, k], {k, 1, n^2 - 1}], {n, 1, 10}] (* Vaclav Kotesovec, Jun 07 2019 *)
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PROG
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(PARI) a(n) = sum(k=1, n^2-1, binomial(2*k, k)); \\ Michel Marcus, Jul 05 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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STATUS
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approved
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