A331268 a(n) is the least divisor u of A331220(n) such that the ternary representations of u and of A331220(n)/u have the same number of digits d for d = 0..2.

1, 2, 3, 4, 5, 5, 6, 7, 8, 9, 10, 10, 11, 12, 11, 13, 14, 11, 14, 15, 11, 16, 15, 17, 14, 15, 18, 16, 19, 17, 19, 20, 17, 21, 20, 22, 23, 23, 24, 25, 26, 27, 28, 28, 29, 30, 29, 31, 28, 32, 30, 32, 33, 31, 34, 31, 32, 35, 34, 36, 29, 32, 37, 34, 37, 38, 32, 33

Offset

1,2

Links

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

Formula

a(n) * A331269(n) = A331220(n).

Prog

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

Crossrefs

Cf. A331220, A331269.

Sequence in context: A332204 A245321 A006163 * A053757 A256562 A228297

Adjacent sequences: A331265 A331266 A331267 * A331269 A331270 A331271

Keyword

nonn,base

Author

Rémy Sigrist, Jan 13 2020

Status

approved