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A090197
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a(n) = n^3 + 6*n^2 + 6*n + 1.
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5
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1, 14, 45, 100, 185, 306, 469, 680, 945, 1270, 1661, 2124, 2665, 3290, 4005, 4816, 5729, 6750, 7885, 9140, 10521, 12034, 13685, 15480, 17425, 19526, 21789, 24220, 26825, 29610, 32581, 35744, 39105, 42670, 46445, 50436, 54649, 59090, 63765
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OFFSET
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0,2
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COMMENTS
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N(4,n) where N(4,x) is the 4th Narayana polynomial.
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LINKS
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FORMULA
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a(n) = N(4,n) = Sum_{k>0} A001263(4, k)*n^(k-1) = (n+1)*(n^2+5*n+1).
G.f.: (1 + 10*x - 5*x^2) / (x-1)^4. - R. J. Mathar, Sep 07 2011
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MATHEMATICA
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LinearRecurrence[{4, -6, 4, -1}, {1, 14, 45, 100}, 40] (* Vincenzo Librandi, Jun 24 2012 *)
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PROG
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(Magma) I:=[1, 14, 45, 100]; [n le 4 select I[n] else 4*Self(n-1)-6*Self(n-2)+4*Self(n-3)-Self(n-4): n in [1..50]]; // Vincenzo Librandi, Jun 24 2012
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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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