OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..10000
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
a(n) = 2*a(n-1) -a(n-2).
G.f.: x*(26-x)/(x-1)^2.
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 *)
PROG
(Magma) I:=[26, 51]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..60]];
(PARI) a(n)=25*n+1 \\ Charles R Greathouse IV, Jun 14 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Mar 12 2009
STATUS
approved