A122425 a(n) = lexicographically greatest divisor of n in decimal representation.

1, 2, 3, 4, 5, 6, 7, 8, 9, 5, 11, 6, 13, 7, 5, 8, 17, 9, 19, 5, 7, 22, 23, 8, 5, 26, 9, 7, 29, 6, 31, 8, 33, 34, 7, 9, 37, 38, 39, 8, 41, 7, 43, 44, 9, 46, 47, 8, 7, 50, 51, 52, 53, 9, 55, 8, 57, 58, 59, 60, 61, 62, 9, 8, 65, 66, 67, 68, 69, 70, 71, 9, 73, 74, 75, 76, 77, 78, 79, 80, 9, 82, 83

Offset

1,2

Comments

a(p) = p for primes p;

a(A122427(n)) = A122427(n), a(A122426(n)) < A122426(n);

a(A122428(n)) = A006530(A122428(n)).

a(n) = A254679(n,A000005(n)). - Reinhard Zumkeller, Feb 05 2015

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Example

Divisors(24) = [1,2,3,4,6,8,12,24] --> [1,12,2,24,3,4,6,8],
therefore a(24) = 8;
divisors(42) = [1,2,3,6,7,14,21,42] --> [1,14,2,21,3,42,6,7],
therefore a(42) = 7.

Prog

(Haskell)
import import Data.List (maximumBy); Data.Ord (comparing)
a122425 = maximumBy (comparing show) . a027750_row
-- Reinhard Zumkeller, Feb 05 2015, Sep 15 2011

Crossrefs

Cf. A254679, A122426, A122427, A122428.

Sequence in context: A051796 A257296 A093030 * A360073 A074044 A079827

Adjacent sequences: A122422 A122423 A122424 * A122426 A122427 A122428

Keyword

nonn,base

Author

Reinhard Zumkeller, Sep 04 2006

Status

approved