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A086025
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a(n) = Sum_{i=1..n} C(i+4,5)^2.
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22
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1, 37, 478, 3614, 19490, 82994, 296438, 923702, 2580071, 6588075, 15606084, 34685508, 72976852, 146387476, 281597860, 521971876, 936053677, 1629533233, 2761788434, 4568378450, 7391175350, 11718183750, 18235516650, 27894475050, 41997225075, 62305185111
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OFFSET
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1,2
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LINKS
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Index entries for linear recurrences with constant coefficients, signature (12,-66,220,-495,792,-924,792,-495, 220,-66,12,-1).
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FORMULA
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G.f.: x*(1+x)*(x^4+24*x^3+76*x^2+24*x+1)/(x-1)^12.
a(n) = n*(2*n+5)*(n+5)*(n+4)*(n+3)*(n+2)*(n+1)*(63*n^4 +630*n^3 +1855*n^2 +1400*n +12) / 19958400. (End)
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MATHEMATICA
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Table[n*(2*n+5)*(n+5)*(n+4)*(n+3)*(n+2)*(n+1)*(63*n^4 +630*n^3 +1855*n^2 +1400*n +12)/19958400, {n, 1, 30}] (* G. C. Greubel, Nov 22 2017 *)
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PROG
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(PARI) for(n=1, 30, print1(sum(i=1, n, binomial(i+4, 5)^2), ", ")) \\ G. C. Greubel, Nov 22 2017
(Magma) [n*(2*n+5)*(n+5)*(n+4)*(n+3)*(n+2)*(n+1)*(63*n^4 +630*n^3 +1855*n^2 +1400*n +12)/19958400: n in [1..30]]; // G. C. Greubel, Nov 22 2017
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CROSSREFS
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Cf. A087127, A024166, A085438, A085439, A085440, A085441, A085442, A086020, A086021, A086022, A086023, A086024, A086026, A086027, A086028, A086029, A086030.
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KEYWORD
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easy,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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