A331269 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.

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, 18, 22, 19, 23, 21, 20, 25, 21, 24, 22, 23, 25, 24, 25, 26, 27, 28, 30, 29, 30, 33, 31, 36, 32, 36, 34, 33, 37, 34, 39, 38, 35, 38, 36, 45, 42, 37, 42, 39, 38, 46, 45

Offset

1,2

Links

Rémy Sigrist, Table of n, a(n) for n = 1..10000

Formula

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

Prog

(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)))))

Crossrefs

Cf. A331220, A331268.

Sequence in context: A071180 A031225 A085729 * A073907 A131424 A336285

Adjacent sequences: A331266 A331267 A331268 * A331270 A331271 A331272

Keyword

nonn,base

Author

Rémy Sigrist, Jan 13 2020

Status

approved