OFFSET
1,3
COMMENTS
Number of numbers in range 1 to n-1 whose decimal expansion is, term-by-term, dominated by n.
EXAMPLE
a(23) = 10 since all the numbers 22, 21, 20, 13, 12, 11, 10, 3, 2, 1 count.
MATHEMATICA
f[n_]:=Module[{idnp=IntegerDigits[n]+1}, Times@@idnp-2]; Array[f, 80](* Harvey P. Dale, May 24 2011 *)
PROG
(PARI) a(n) = vecprod(apply(x->x+1, digits(n))) - 2; \\ Michel Marcus, Oct 06 2021
CROSSREFS
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, May 17 2011
STATUS
approved