OFFSET
1,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..200
Eric Weisstein's World of Mathematics, Halved Cube Graph
Eric Weisstein's World of Mathematics, Molecular Topological Index
Index entries for linear recurrences with constant coefficients, signature (26,-296,1936,-8016,21792,-38912, 44032,-28672,8192).
FORMULA
a(n) = 2^(n-3)*n^2*(n-1)*(n-1+2^(n-2)). - Andrew Howroyd, May 11 2017
a(n) = 26*a(n-1) - 296*a(n-2) + 1936*a(n-3) - 8016*a(n-4) + 21792*a(n-5) - 38912*a(n-6) + 44032*a(n-7) - 28672*a(n-8) + 8192*a(n-9). - Eric W. Weisstein, May 27 2017
G.f.: 4*x^2*(1 - 8*x - 4*x^2 + 224*x^3 - 744*x^4 + 576*x^5 + 480*x^6)/((1-4*x)^4*(1-2*x)^5). - Eric W. Weisstein, May 27 2017
E.g.f.: x^2*(1 + 4*x + 2*x^2 + (1+2*x)*exp(2*x))*exp(2*x). - G. C. Greubel, Jan 04 2019
MATHEMATICA
Table[2^(-5+n)*(-1+n)*n^2*(-4 +2^n +4n), {n, 30}] (* Eric W. Weisstein, May 27 2017 *)
LinearRecurrence[{26, -296, 1936, -8016, 21792, -38912, 44032, -28672, 8192}, {0, 4, 72, 672, 4800, 30240, 178752, 1017856, 5640192}, 30] (* Eric W. Weisstein, May 27 2017 *)
Rest@CoefficientList[Series[(4x^2 (1-8x -4x^2 +224x^3 -744x^4 +576x^5 + 480 x^6)/((1-4x)^4 (1-2x)^5)), {x, 0, 30}], x] (* Eric W. Weisstein, May 27 2017 *)
PROG
(PARI) vector(30, n, 2^(n-3)*n^2*(n-1)*(n-1+2^(n-2))) \\ G. C. Greubel, Jan 04 2019
(Magma) [2^(n-3)*n^2*(n-1)*(n-1+2^(n-2)): n in [1..30]]; // G. C. Greubel, Jan 04 2019
(Sage) [2^(n-3)*n^2*(n-1)*(n-1+2^(n-2)) for n in (1..30)] # G. C. Greubel, Jan 04 2019
(GAP) List([1..30], n -> 2^(n-3)*n^2*(n-1)*(n-1+2^(n-2))); # G. C. Greubel, Jan 04 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric W. Weisstein, Jul 11 2011
EXTENSIONS
a(11)-a(22) from Andrew Howroyd, May 11 2017
STATUS
approved