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A065850 Let u be any string of n digits from {0,...,8}; 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, 5, 11, 39, 161, 865, 4604, 22636, 161107, 840691 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..11.

EXAMPLE

a(2)=2 because 12 and 21 (written in base 9) are primes (11 and 19).

MATHEMATICA

c[x_] := Module[{},

   Length[Select[Permutations[x],

     First[#] != 0 && PrimeQ[FromDigits[#, 9]] &]]];

A065850[n_] := Module[{i},

   Return[Max[Map[c, DeleteDuplicatesBy[Tuples[Range[0, 8], n],

       Table[Count[#, i], {i, 0, 8}] &]]]]];

Table[A065850[n], {n, 1, 7}] (* Robert Price, Mar 30 2019 *)

CROSSREFS

Cf. A065843, A065844, A065845, A065846, A065847, A065848, A065849, A065851, A065852, A065853

Sequence in context: A001344 A056302 A276547 * A191029 A106886 A237814

Adjacent sequences:  A065847 A065848 A065849 * A065851 A065852 A065853

KEYWORD

base,more,nonn

AUTHOR

Sascha Kurz, Nov 24 2001

EXTENSIONS

2 more terms 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 22 14:02 EST 2020. Contains 331149 sequences. (Running on oeis4.)