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A111400
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P(P(n)) - P(P(n-1)), where P(n) = (n+1)*(n+2)*(n+3)/6 (see A000292).
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2
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0, 3, 31, 251, 1485, 6665, 24073, 73486, 196626, 473595, 1047255, 2157793, 4189991, 7736001, 13676705, 23285020, 38354788, 61359171, 95642751, 145651815, 217207585, 317827433, 457099401, 647115626, 902970550, 1243330075, 1691078103, 2274047181
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OFFSET
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0,2
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LINKS
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FORMULA
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a(n) = 9*a(n-1) - 36*a(n-2) + 84*a(n-3) - 126*a(n-4) + 126*a(n-5) - 84*a(n-6) + 36*a(n-7) - 9*a(n-8) + a(n-9).
G.f.: x*(x^6 - 8*x^5 + 110*x^4 + 90*x^3 + 80*x^2 + 4*x + 3)/(1 - x)^9. (End)
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MATHEMATICA
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LinearRecurrence[{9, -36, 84, -126, 126, -84, 36, -9, 1}, {0, 3, 31,
251, 1485, 6665, 24073, 73486, 196626}, 100] (* G. C. Greubel, May 27 2016 *)
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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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