Voozh

A065853

Let u be any string of 4 digits from {0,...,n-1}; let f(u) = number of distinct primes, not beginning with 0, formed by permuting the digits of u to a base-n number; then a(n) = max_u f(u).

2, 4, 6, 7, 8, 15, 11, 11, 11, 15, 15, 19, 11, 14, 15, 14, 11, 16, 13, 18, 14, 14, 14, 16, 13, 16, 15, 17, 13, 16, 14, 15, 17, 16, 15, 16, 14, 17, 14, 17, 16, 17, 14, 16, 15, 15, 14, 17, 17, 16, 16, 16, 15, 18, 16, 17, 14, 15, 14, 16, 15, 15, 16, 16, 17, 17, 13, 17, 15, 17, 13

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OFFSET

2,1

LINKS

Table of n, a(n) for n=2..72.

EXAMPLE

a(2)=2 because 1101 and 1011 are primes and there are no three 4-digit primes with the same number of ones in base 2.

MATHEMATICA

c[x_, n_] :=

Module[{},

Length[Select[Permutations[x],

First[#] != 0 && PrimeQ[FromDigits[#, n]] &]]];