A023095 a(n) is the least k > 0 such that k and 3k are anagrams in base n (written in base 10).

75, 142, 315, 12, 819, 84, 1035, 15, 198, 2766, 9555, 56, 315, 8352, 20893, 45, 950, 22000, 819, 132, 63204, 24492, 114075, 91, 2646, 938, 30015, 240, 182807, 118592, 333795, 153, 5670, 187416, 73815, 380, 623610, 176820, 5699, 231, 10406, 489808

Offset

4,1

Comments

2*a(n) is divisible by n-1. - Robert Israel, Mar 20 2017

Links

Table of n, a(n) for n=4..45.

Maple

for n from 4 to 100 do
  searching:= true:
  if n::even then delta:= n-1 else delta:= (n-1)/2 fi;
  for d from 1 while searching do
    for x from n^(d-1)+delta-1 to floor(n^d/3) by delta while searching do
      if sort(convert(x, base, n)) = sort(convert(3*x, base, n)) then
        searching:= false; A[n]:= x;
      fi
od od od:
seq(A[i], i=4..100); # Robert Israel, Mar 20 2017

Mathematica

Table[k = 1; While[! Equal @@ Map[Sort@ IntegerDigits[#, n] &, {k, 3 k}], k++]; k, {n, 4, 45}] (* Michael De Vlieger, Mar 20 2017 *)

Crossrefs

Sequence in context: A118225 A260538 A361487 * A044326 A044707 A228306

Adjacent sequences: A023092 A023093 A023094 * A023096 A023097 A023098

Keyword

nonn,base

Author

David W. Wilson

Status

approved