A158060 a(n) = 25*n + 1.

26, 51, 76, 101, 126, 151, 176, 201, 226, 251, 276, 301, 326, 351, 376, 401, 426, 451, 476, 501, 526, 551, 576, 601, 626, 651, 676, 701, 726, 751, 776, 801, 826, 851, 876, 901, 926, 951, 976, 1001, 1026, 1051, 1076, 1101, 1126, 1151, 1176, 1201, 1226, 1251

Offset: 1

Author

Vincenzo Librandi, Mar 12 2009

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..10000
• Index entries for linear recurrences with constant coefficients, signature (2,-1).

Programs

Magma

I:=[26, 51]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..60]];

Mathematica

LinearRecurrence[{2,-1},{26,51},50]
Range[26, 2000, 25] (* Vladimir Joseph Stephan Orlovsky, Jun 14 2011 *)
25*Range[50]+1 (* Harvey P. Dale, Nov 23 2018 *)

PARI

a(n)=25*n+1 \\ Charles R Greathouse IV, Jun 14 2011

Formula

a(n) = 2*a(n-1) - a(n-2).

G.f.: x*(26-x)/(x-1)^2.

E.g.f.: exp(x)*(25*x + 1) - 1. - Elmo R. Oliveira, Apr 03 2025