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 A027001 a(n) = T(2*n, n+2), T given by A026998. 1
 1, 26, 174, 743, 2552, 7784, 22193, 60882, 163430, 433495, 1142496, 3001056, 7869649, 20619098, 54001422, 141401879, 370224248, 969294632, 2537687585, 6643800690, 17393752166, 45537499111, 119218794624, 312118940928, 817138091617, 2139295405274 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,2 LINKS Colin Barker, Table of n, a(n) for n = 2..1000 Index entries for linear recurrences with constant coefficients, signature (7,-19,26,-19,7,-1). FORMULA a(n-2) = 3*F(2n+10)-2*F(2n+9)-F(2n+8)-4n^3-26n^2-68n-75, F(n) = A000045(n). - Ralf Stephan, Feb 07 2004 From Colin Barker, Feb 18 2016: (Start) a(n) = (2^(-1-n)*(-11*2^(1+n)+(11-5*sqrt(5))*(3-sqrt(5))^n+(3+sqrt(5))^n*(11+5*sqrt(5)))-12*n-2*n^2-4*n^3). G.f.: x^2*(1+x)*(1+18*x-7*x^2) / ((1-x)^4*(1-3*x+x^2)). (End) MATHEMATICA LinearRecurrence[{7, -19, 26, -19, 7, -1}, {1, 26, 174, 743, 2552, 7784}, 30] (* Vincenzo Librandi, Feb 19 2016 *) PROG (PARI) Vec(x^2*(1+x)*(1+18*x-7*x^2)/((1-x)^4*(1-3*x+x^2)) + O(x^40)) \\ Colin Barker, Feb 18 2016 (Magma) [3*Fibonacci(2*n+10)-2*Fibonacci(2*n+9)-Fibonacci(2*n+8)-4*n^3-26*n^2-68*n-75: n in [0..30]]; // Vincenzo Librandi, Feb 19 2016 CROSSREFS Bisection of A027964. Sequence in context: A125336 A321113 A126494 * A173893 A252936 A218083 Adjacent sequences: A026998 A026999 A027000 * A027002 A027003 A027004 KEYWORD nonn,easy AUTHOR Clark Kimberling STATUS approved

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Last modified September 22 14:29 EDT 2023. Contains 365531 sequences. (Running on oeis4.)