A014909 a(1)=1, a(n) = 23*a(n-1) + n.

1, 25, 578, 13298, 305859, 7034763, 161799556, 3721389796, 85591965317, 1968615202301, 45278149652934, 1041397442017494, 23952141166402375, 550899246827254639, 12670682677026856712, 291425701571617704392

Offset

1,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..200

Index entries for linear recurrences with constant coefficients, signature (25, -47, 23).

Formula

a(1)=1, a(2)=25, a(3)=578, a(n) = 25*a(n-1) - 47*a(n-2) + 23*a(n-3). - Harvey P. Dale, Feb 05 2012

G.f.: -(x/((-1+x)^2*(-1+23*x))). - Harvey P. Dale, Feb 05 2012

Mathematica

Transpose[NestList[{First[#]+1, 23Last[#]+First[#]+1}&, {1, 1}, 20]][[2]] (* or *) LinearRecurrence[{25, -47, 23}, {1, 25, 578}, 20] (* Harvey P. Dale, Feb 05 2012 *)

Prog

(Magma) I:=[1, 25, 578]; [n le 3 select I[n] else 25*Self(n-1)-47*Self(n-2)+23*Self(n-3): n in [1..30]]; // Vincenzo Librandi, Feb 05 2012

Crossrefs

Sequence in context: A264378 A015679 A230454 * A239822 A264220 A228827

Adjacent sequences: A014906 A014907 A014908 * A014910 A014911 A014912

Keyword

nonn,easy

Author

N. J. A. Sloane, Olivier Gérard

Status

approved