OFFSET
1,1
LINKS
Paolo P. Lava, Table of n, a(n) for n = 1..100
EXAMPLE
Aliquot parts of 157442 are 1, 2, 78621; their concatenation in ascending order is concat(1,2,78621) = 1278621, which is a palindrome.
MAPLE
with(numtheory): P:=proc(q) local a, b, c, k, n;
for n from 2 to q do if not isprime(n) then a:=sort([op(divisors(n))]); b:=0;
for k from nops(a)-1 by -1 to 1 do b:=b*10^(ilog10(a[k])+1)+a[k]; od; a:=0; c:=b;
for k from 1 to ilog10(b)+1 do a:=10*a+(c mod 10); c:=trunc(c/10); od;
if a=b then print(n); fi; fi; od; end: P(10^9);
PROG
(PARI) isok(n) = {d = vecsort(divisors(n)); if (#d > 2, s = ""; for (i=1, #d-1, s = concat(s, Str(d[i])); ); d = digits(eval(s)); d == Vecrev(d); ); } \\ Michel Marcus, Oct 25 2014
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Paolo P. Lava, Oct 24 2014
STATUS
approved