OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..1000
EXAMPLE
105 is a term as 015 is a proper divisor of 105.
2178 is a proper divisor of 8712 and 8712/2178=4.
1089 is a proper divisor of 9801 and 9801/1089=9.
MAPLE
filter:= proc(n) local L, nL, P;
L:= convert(n, base, 10);
nL:= nops(L);
P:= subs(L=NULL, combinat:-permute(L));
ormap(p -> n mod add(p[i]*10^(i-1), i=1..nL) = 0, P)
end proc:
select(filter, [seq(seq(10*i+j, j=1..9), i=1..10000)]); # Robert Israel, Jun 01 2020
MATHEMATICA
f[n_] := Union[ IntegerQ /@ Drop[ n/FromDigits /@ Permutations[IntegerDigits[n]], 1]][[ -1]]; Select[ Range[ 9015], Mod[ #, 10] != 0 && f[ # ] == True &] (* Robert G. Wilson v, Jun 23 2004 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Jun 22 2004
EXTENSIONS
Edited, corrected and extended by Robert G. Wilson v, Jun 23 2004
STATUS
approved