OFFSET
0,2
LINKS
Index entries for linear recurrences with constant coefficients, signature (10,-27,18).
FORMULA
a(n) = 9*a(n-1) - 18*a(n-2) + 1. - Vincenzo Librandi, Feb 10 2011
a(n) = 2*6^(n+1)/5 - 3^(n+1)/2 + 1/10. - R. J. Mathar, Feb 10 2011
a(n) = Sum_{k=0...n} 2^(k-1)*(3^(n+1) - 3^k). - J. M. Bergot, Feb 06 2018
MAPLE
a:=n->sum((6^(n-j+1)-3^(n-j+1))/3, j=0..n+1): seq(a(n), n=0..19); # Zerinvary Lajos, Jan 15 2007
PROG
(PARI) Vec(1/((1-x)*(1-3*x)*(1-6*x))+O(x^99)) \\ Charles R Greathouse IV, Sep 26 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved