OFFSET
0,2
COMMENTS
Number of integers from 0 to 10^(n+1)-1 that lack any particular digit other than 0. - Robert G. Wilson v, Apr 14 2003
These are the numbers 888...8 in base 9. - Zerinvary Lajos, Nov 21 2007
LINKS
FORMULA
G.f.: 1/(1-9*x)-1/(1-x). - Mohammad K. Azarian, Jan 14 2009
E.g.f.: e^(9*x)-e^x. - Mohammad K. Azarian, Jan 14 2009
a(n) = 9*a(n-1)+8 for n>0, a(0)=0. - Vincenzo Librandi, Nov 19 2010
a(0)=0, a(1)=8; for n>1, a(n) = 10*a(n-1)-9*a(n-2). - Harvey P. Dale, Apr 14 2015
a(n) = Sum_{i=1..n} 8^i*binomial(n,n-i) for n>0, a(0)=0. - Bruno Berselli, Nov 11 2015
a(n) = A001019(n) - 1. - Sean A. Irvine, Jun 19 2019
Sum_{n>=1} 1/a(n) = A248726. - Amiram Eldar, Nov 13 2020
MATHEMATICA
Table[9^n - 1, {n, 0, 20}]
LinearRecurrence[{10, -9}, {0, 8}, 30] (* Harvey P. Dale, Apr 14 2015 *)
PROG
(PARI) a(n)=9^n-1 \\ Charles R Greathouse IV, Jun 11 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved