OFFSET
0,2
COMMENTS
Number of distinct n-digit suffixes of base 4 squares.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..170
Index entries for linear recurrences with constant coefficients, signature (5, -4).
FORMULA
a(n) = floor((4^n+10)/6).
Also, a(0)=1 and, for n>0, a(n) = (4^n+8)/6. - Bruno Berselli, Jul 27 2010
G.f.: (1-3*x-2*x^2)/((1-x)*(1-4*x)). - Bruno Berselli, Jul 27 2010
a(n)-5*a(n-1)+4*a(n-2) = 0 for n>1. - Bruno Berselli, Jul 27 2010
PROG
(Magma) [Floor((4^n+10)/6): n in [0..40] ]; // Vincenzo Librandi, Apr 28 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved