OFFSET
0,2
COMMENTS
Sum of n-th row of triangle of powers of 8: 1; 1 8 1; 1 8 64 8 1; 1 8 64 512 64 8 1; ...
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (9, -8).
FORMULA
G.f.: (1+x)/((1-x)*(1-8*x)).
a(n) = 8*a(n-1) + 2, a(0) = 1.
a(n) = 9*a(n-1) - 8*a(n-2), a(0) = 1, a(1) = 10.
a(n) = Sum_{k=0..n} A112468(n,k)*9^k.
EXAMPLE
a(0) = 1;
a(1) = 1 + 8 + 1 = 10;
a(2) = 1 + 8 + 64 + 8 + 1 = 82;
a(3) = 1 + 8 + 64 + 512 + 64 + 8 + 1 = 658; etc.
MATHEMATICA
Table[(9 8^n - 2)/7, {n, 0, 50}] (* Vincenzo Librandi, Feb 23 2014 *)
PROG
(Magma) [(9*8^n - 2)/7: n in [0..30]]; // Vincenzo Librandi, Feb 23 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Philippe Deléham, Feb 21 2014
EXTENSIONS
Corrected by Vincenzo Librandi, Feb 23 2014
STATUS
approved