OFFSET
0,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..1000
FORMULA
G.f.: Product_{i>=1} 1/(1-10*x^i).
a(n) ~ c * 10^n, where c = Product_{k>=1} 1/(1-1/10^k) = 1.12358275484865251117... . - Vaclav Kotesovec, Mar 19 2015
MAPLE
b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0,
b(n, i-1) +`if`(i>n, 0, 10*b(n-i, i))))
end:
a:= n-> b(n$2):
seq(a(n), n=0..25);
MATHEMATICA
(O[x]^20 - 9/QPochhammer[10, x])[[3]] (* Vladimir Reshetnikov, Nov 20 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 08 2014
STATUS
approved