A076084 Consider all numbers that can be formed by permuting the digits of n; take those with the greatest number of divisors; a(n) is the smallest of them.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 91, 20, 12, 22, 32, 24, 52, 26, 72, 28, 92, 30, 13, 32, 33, 34, 35, 36, 37, 38, 39, 40, 14, 24, 34, 44, 54, 64, 74, 84, 94, 50, 15, 52, 35, 54, 55, 56, 75, 58, 95, 60, 16, 26, 36, 64, 56, 66, 76, 68, 96, 70, 17, 72

Offset: 1

Author

Amarnath Murthy, Oct 07 2002

Keywords

• nonn
• base
• look

Examples

			a(24)=a(42) = 24. a(61) = 16.
From the numbers found by permuting the digits 1138, we get 1138, 1183, 1318, 1381, 1813, 1831, 3118, 3181, 3811, 8113, 8131 and 8311. We find that 8113 has the most divisors of those, namely 8. Therefore a(1138) = 8113. - _David A. Corneth_, Apr 22 2016
		

Links

• David A. Corneth, Table of n, a(n) for n = 1..10000 (First 1000 terms from Harvey P. Dale)

Crossrefs

Cf. A261370.

Programs

Mathematica

pdn[n_]:=Module[{c=SortBy[{#,DivisorSigma[0,#]}&/@FromDigits/@ Permutations[ IntegerDigits[n]],Last],m},m=c[[-1,2]];Min[Transpose[ Select[c,#[[2]]==m&]][[1]]]]; Array[pdn,80] (* Harvey P. Dale, Nov 29 2013 *)

Extensions

More terms from David Wasserman, Mar 24 2005