A331269 - OEIS

%I #11 Jan 13 2020 18:26:06

%S 1,2,3,4,5,7,6,7,8,9,10,12,11,12,15,13,14,19,16,15,21,16,19,17,22,21,

%T 18,22,19,23,21,20,25,21,24,22,23,25,24,25,26,27,28,30,29,30,33,31,36,

%U 32,36,34,33,37,34,39,38,35,38,36,45,42,37,42,39,38,46,45

%N a(n) is the greatest divisor v of A331220(n) such that the ternary representations of v and of A331220(n)/v have the same number of digits d for d = 0..2.

%H Rémy Sigrist, <a href="/A331269/b331269.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) * A331268(n) = A331220(n).

%o (PARI) b=3; k=68; for (n=1, oo, fordiv (n, u, if (vecsort(digits(u,b))==vecsort(digits(v=n/u,b)), print1 (v", "); break (if (k--, 1, 2)))))

%Y Cf. A331220, A331268.

%K nonn,base

%O 1,2

%A _Rémy Sigrist_, Jan 13 2020