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A081907
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A sequence related to binomial(n+2, 2).
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2
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1, 8, 61, 450, 3240, 22896, 159408, 1096416, 7464960, 50388480, 337602816, 2247326208, 14874679296, 97955205120, 642150789120, 4192482779136, 27270729105408, 176789554200576, 1142549512519680, 7363096858460160
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OFFSET
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0,2
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COMMENTS
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5th binomial transform of binomial(n+2, 2), A000217.
6th binomial transform of (1,2,1,0,0,0,...).
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LINKS
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FORMULA
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a(n) = 6^n*(n^2 + 23*n + 72)/72.
G.f.: (1-5*x)^2/(1-6*x)^3.
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MAPLE
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seq(coeff(series((1-5*x)^2/(1-6*x)^3, x, n+1), x, n), n = 0 .. 20); # Muniru A Asiru, Oct 18 2018
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MATHEMATICA
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Table[6^n*(n^2+23*n+72)/72, {n, 0, 50}] (* or *) LinearRecurrence[{18, -108, 216}, {1, 8, 61}, 50] (* G. C. Greubel, Oct 17 2018 *)
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PROG
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(PARI) vector(50, n, n--; 6^n*(n^2 +23*n +72)/72) \\ G. C. Greubel, Oct 17 2018
(Magma) [6^n*(n^2 +23*n +72)/72: n in [0..50]]; // G. C. Greubel, Oct 17 2018
(GAP) List([1..20], n->6^(n-1)*(n^2+21*n+50))/72; # Muniru A Asiru, Oct 18 2018
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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