A076084 - OEIS

%I #19 Apr 22 2016 23:51:56

%S 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,

%T 72,28,92,30,13,32,33,34,35,36,37,38,39,40,14,24,34,44,54,64,74,84,94,

%U 50,15,52,35,54,55,56,75,58,95,60,16,26,36,64,56,66,76,68,96,70,17,72

%N 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.

%H David A. Corneth, <a href="/A076084/b076084.txt">Table of n, a(n) for n = 1..10000</a> (First 1000 terms from Harvey P. Dale)

%e a(24)=a(42) = 24. a(61) = 16.

%e 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

%t 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 *)

%Y Cf. A261370.

%K nonn,base,look

%O 1,2

%A _Amarnath Murthy_, Oct 07 2002

%E More terms from _David Wasserman_, Mar 24 2005