A195856 a(n) = T(10,n), array T given by A048505.

1, 122, 387, 965, 2221, 4941, 10813, 23453, 50589, 108701, 232861, 497565, 1060765, 2256797, 4792221, 10157981, 21495709, 45416349, 95813533, 201850781, 424673181, 892338077, 1872756637, 3925868445, 8220835741, 17196646301

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..2000

Index entries for linear recurrences with constant coefficients, signature (7,-18,20,-8).

Formula

a(n) = (n^2+41*n+400)*2^(n-2)-99.

a(n) = 7*a(n-1)-18*a(n-2)+20*a(n-3)-8*a(n-4). - Colin Barker, Feb 25 2015

G.f.: (432*x^3-449*x^2+115*x+1) / ((x-1)*(2*x-1)^3). Colin Barker, Feb 25 2015

Mathematica

LinearRecurrence[{7, -18, 20, -8}, {1, 122, 387, 965}, 30] (* Harvey P. Dale, Dec 29 2014 *)

Prog

(Magma) [(n^2+41*n+400)*2^(n-2)-99: n in [0..30]]
(PARI) a(n)=(n^2+41*n+400)<<(n-2)-99 \\ Charles R Greathouse IV, Dec 27 2011
(PARI) Vec((432*x^3-449*x^2+115*x+1) / ((x-1)*(2*x-1)^3) + O(x^100)) \\ Colin Barker, Feb 25 2015

Crossrefs

Cf. A048506, A048507, A048508, A048509, A048510, A048511, A048512, A048513, A048514, A048515, A195855.

Sequence in context: A276303 A224598 A070955 * A116216 A203805 A275270

Adjacent sequences: A195853 A195854 A195855 * A195857 A195858 A195859

Keyword

nonn,easy,less

Author

Vincenzo Librandi, Sep 25 2011

Status

approved