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A331271
a(n) is the greatest divisor v of A331221(n) such that the decimal representations of v and of A331221(n)/v have the same number of digits d for d = 0..9.
3
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 21, 16, 17, 18, 19, 20, 31, 21, 22, 23, 41, 24, 25, 26, 27, 32, 51, 28, 29, 30, 31, 61, 42, 32, 33, 34, 71, 35, 36, 52, 37, 38, 81, 43, 39, 40, 62, 41, 91, 42, 43, 53, 44, 72, 45, 46, 47, 63, 82, 48, 49, 54
OFFSET
1,2
LINKS
FORMULA
a(n) * A331270(n) = A331221(n).
PROG
(PARI) b=10; k=67; 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
Sequence in context: A052060 A084688 A194898 * A267016 A023769 A023796
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Jan 13 2020
STATUS
approved