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A065852 Let u be any string of 3 digits from {0,...,n-1}; let f(u) = number of distinct primes, not beginning with 0, formed by permuting the digits of u; then a(n) = max_u f(u). 10

%I

%S 1,2,3,4,4,5,3,5,4,6,4,6,4,5,5,5,4,6,5,6,5,6,5,6,5,6,5,6,5,6,5,6,6,6,

%T 6,6,5,6,6,6,5,6,6,6,6,5,5,6,6,6,6,6,5,6,6,6,5,6,6,6,6,6,6,6,6,6,5,6,

%U 6,6,5,6,6,6,6,6,6,6,6,6

%N Let u be any string of 3 digits from {0,...,n-1}; let f(u) = number of distinct primes, not beginning with 0, formed by permuting the digits of u; then a(n) = max_u f(u).

%C a(192)=5 and a(n)=6 for all 73<n<985.

%e a(2)=1 because 101 is prime and there are no two 3-digit primes with the same number of ones in base two.

%t c[x_, n_] :=

%t Module[{},

%t Length[Select[Permutations[x],

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

%t A065852[n_] := Module[{i},

%t Return[ Max[Map[c[#, n] &, DeleteDuplicatesBy[Tuples[Range[0, n - 1], 3], Table[Count[#, i], {i, 0, n - 1}] &]]]]];

%t Table[A065852[n], {n, 2, 30}] (* _Robert Price_, Mar 30 2019 *)

%Y Cf. A065843, A065844, A065845, A065846, A065847, A065848, A065849, A065850, A065851, A065853

%K base,nonn

%O 2,2

%A _Sascha Kurz_, Nov 24 2001

%E Definition corrected by _David A. Corneth_, Apr 23 2016

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Last modified February 22 15:05 EST 2020. Contains 332137 sequences. (Running on oeis4.)