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A144485
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a(n) = (3n + 2)*binomial(3n + 1,n).
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2
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2, 20, 168, 1320, 10010, 74256, 542640, 3922512, 28120950, 200300100, 1419269280, 10013421600, 70394353848, 493362138080, 3448674255840, 24051721745568, 167405449649550, 1163116182943260, 8068463611408200, 55891260077406600
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OFFSET
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0,1
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LINKS
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FORMULA
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MAPLE
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a:= proc(n) option remember; `if`(n=0, 2,
3*(3*n+1)*(3*n+2)*a(n-1)/(2*n*(2*n+1)))
end:
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MATHEMATICA
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a[k_] = (3k + 2)Binomial[3k + 1, k]; Table[a[k], {k, 0, 30}]
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PROG
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(Magma) [(3*n+2)*Binomial(3*n+1, n): n in [0..20]]; // Vincenzo Librandi, Feb 14 2014
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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