OFFSET
0,1
COMMENTS
Numbers k such that k^k ends with 9. - Bruno Berselli, Dec 11 2018
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..5000
Tanya Khovanova, Recursive Sequences
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 979
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
a(n) = 10*n + 9; a(n) = 2*a(n-1) - a(n-2). - Vincenzo Librandi, May 29 2011
G.f.: ( 9+x ) / (x-1)^2 . - R. J. Mathar, Oct 16 2015
MATHEMATICA
Range[9, 1000, 10] (* Vladimir Joseph Stephan Orlovsky, May 28 2011 *)
PROG
(Magma) [10*n+9: n in [0..60]]; // Vincenzo Librandi, May 29 2011
(PARI) a(n)=10*n+9 \\ Charles R Greathouse IV, Feb 12 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved