OFFSET
0,2
COMMENTS
n-th difference of a(n), a(n-1), ..., a(0) is (9, 9, 9, ...).
LINKS
FORMULA
a(n) = 9 * 2^n - 8. - Ralf Stephan
Equals binomial transform of [1, 9, 9, 9, ...]. - Gary W. Adamson, Apr 29 2008
a(n) = 2*a(n-1) + 8, with a(0)=1. - Vincenzo Librandi, Aug 06 2010
a(n) = 2*A053209(n), n>0. - Philippe Deléham, Apr 15 2013
a(n) = 3*a(n-1) - 2*a(n-2) with a(0)=1, a(1)=10. - Philippe Deléham, Apr 15 2013
G.f.: (1+7*x)/((1-x)*(1-2*x)). - Philippe Deléham, Apr 15 2013
MATHEMATICA
a=1; lst={a}; k=9; Do[a+=k; AppendTo[lst, a]; k+=k, {n, 0, 5!}]; lst (* Vladimir Joseph Stephan Orlovsky, Dec 16 2008 *)
9*2^Range[0, 30]-8 (* Harvey P. Dale, May 14 2021 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved