OFFSET
1,1
LINKS
Hiroaki Yamanouchi, Table of n, a(n) for n = 1..35
EXAMPLE
For n=1, the five 1-digit integers 0,1,2,3,4 satisfy the condition, with results being respectively 0,2,4,6 and 8, hence a(1)=5.
PROG
(PARI) DP(n)= my(d = digits(n)); prod(i=1, #d, d[i]);
a(n) = {nb = 0; if (n==1, istart = 0, istart = 10^(n-1)); for (i=istart, 10^n-1, if (i + DP(i) < 10^n, nb++); ); nb; }
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Michel Marcus, Jun 01 2014
EXTENSIONS
a(9)-a(17) from Hiroaki Yamanouchi, Sep 29 2014
a(18)-a(20) from Hiroaki Yamanouchi, Jan 08 2016
STATUS
approved