%I #10 Jan 13 2020 18:25:57
%S 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,12,16,17,18,19,20,13,21,22,23,14,
%T 24,25,26,27,23,15,28,29,30,31,16,24,32,33,34,17,35,36,25,37,38,18,34,
%U 39,40,26,41,19,42,43,35,44,27,45,46,47,36,28,48,49,45
%N a(n) is the least divisor u of A331221(n) such that the decimal representations of u and of A331221(n)/u have the same number of digits d for d = 0..9.
%H Rémy Sigrist, <a href="/A331270/b331270.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) * A331271(n) = A331221(n).
%o (PARI) b=10; k=67; for (n=1, oo, fordiv (n, u, if (vecsort(digits(u,b))==vecsort(digits(n/u,b)), print1 (u", "); break (if (k--, 1, 2)))))
%Y Cf. A331221, A331271.
%K nonn,base
%O 1,2
%A _Rémy Sigrist_, Jan 13 2020