OFFSET
0,2
COMMENTS
Main diagonal of array defined by m(0,j) = j; m(i,0) = i and m(i,j) = m(i-1,j) + 8*m(i-1,j-1). - Benoit Cloitre, Jun 13 2003
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..300
Index entries for linear recurrences with constant coefficients, signature (18, -81).
FORMULA
a(n) = 18*a(n-1) - 81*a(n-2), a(0) = 1, a(1) = 10.
a(n) = (n + 9)*9^(n-1).
G.f.: (1 - 8*x)/(1 - 9*x)^2.
E.g.f.: exp(9*x)*(1 + x). - Stefano Spezia, Mar 04 2023
MATHEMATICA
CoefficientList[Series[(1 - 8 x) / (1 - 9 x)^2, {x, 0, 30}], x] (* Vincenzo Librandi, Aug 06 2013 *)
PROG
(Magma) [(n+9)*9^(n-1): n in [0..25]]; // Vincenzo Librandi, Aug 06 2013
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Mar 07 2003
STATUS
approved