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 A065851 Let u be any string of n digits from {0,...,9}; 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
 1, 2, 4, 11, 39, 148, 731, 4333, 26519, 152526 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS EXAMPLE a(2)=2 because 13 and 31 are primes. a(3) because {149, 419, 491, 941} or {179, 197, 719, 971} or {379, 397, 739, 937} are primes. - R. J. Mathar, Apr 23 2016 MATHEMATICA c[x_] := Module[{},    Length[Select[Permutations[x],      First[#] != 0 && PrimeQ[FromDigits[#, 10]] &]]]; A065851[n_] := Module[{i},    Return[Max[Map[c, DeleteDuplicatesBy[Tuples[Range[0, 9], n],        Table[Count[#, i], {i, 0, 9}] &]]]]]; Table[A065851[n], {n, 1, 6}] (* Robert Price, Mar 30 2019 *) CROSSREFS Cf. A065843, A065844, A065845, A065846, A065847, A065848, A065849, A065850, A065852, A065853 Sequence in context: A101898 A193188 A216810 * A173938 A242790 A013044 Adjacent sequences:  A065848 A065849 A065850 * A065852 A065853 A065854 KEYWORD base,more,nonn AUTHOR Sascha Kurz, Nov 24 2001 EXTENSIONS 1 more term from Sean A. Irvine, Sep 06 2009 Definition corrected by David A. Corneth, Apr 23 2016 STATUS approved

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Last modified January 17 23:37 EST 2020. Contains 330995 sequences. (Running on oeis4.)