OFFSET
1,2
COMMENTS
If n is divisible by a prime larger than 7, then n can't divide prod(m), so a(n)=0. Are there any other values of n with a(n)=0?
EXAMPLE
a(2)=88 because prod(88)=64, sum(88)=16, length(88)=2, n=2 and 64=2*2*16.
MATHEMATICA
id := IntegerDigits; prod[n_] := Times@@id[n]; l[n_] := Length[id[n]]; sum[n_] := Plus@@id[n]; a[n_] := If[FactorInteger[2n][[ -1, 1]]>7, 0, For[m=1, True, m++, If[prod[m]==n*l[m]sum[m], Return[m]]]]
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Felice Russo, Sep 18 2001
EXTENSIONS
Corrected by Larry Reeves (larryr(AT)acm.org), Sep 20 2001
Edited by Dean Hickerson, Jun 02 2002
STATUS
approved