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A290986
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Expansion of x^6/((1 - x)^2*(1 - 2*x + x^3 - x^4)).
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3
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1, 4, 11, 25, 52, 103, 199, 379, 716, 1346, 2523, 4721, 8825, 16487, 30791, 57494, 107343, 200400, 374116, 698403, 1303770, 2433846, 4543428, 8481513, 15832975, 29556394, 55174730, 102998026, 192272662, 358927018, 670030771
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OFFSET
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6,2
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LINKS
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FORMULA
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MAPLE
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f:= gfun:-rectoproc({a(n)-a(n+1)+2*a(n+3)-a(n+4)+n-1, a(0) = 0, a(1) = 0, a(2) = 0, a(3) = 0, a(4) = 0, a(5) = 0, a(6) = 1}, a(n), remember):
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MATHEMATICA
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LinearRecurrence[{4, -5, 1, 3, -3, 1}, {1, 4, 11, 25, 52, 103}, 40] (* Vincenzo Librandi, Aug 17 2017 *)
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PROG
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(PARI) Vec(x^6/((1-x)^2*(1-2*x+x^3-x^4)) + O(x^50)) \\ Michel Marcus, Aug 17 2017
(Magma) I:=[1, 4, 11, 25, 52, 103]; [n le 6 select I[n] else 4*Self(n-1)-5*Self(n-2)+Self(n-3)+3*Self(n-4)-3*Self(n-5)+Self(n-6): n in [1..40]]; // Vincenzo Librandi, Aug 17 2017
(SageMath)
P.<x> = PowerSeriesRing(ZZ, prec)
return P( x^6/((1-x)^2*(1-2*x+x^3-x^4)) ).list()
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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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