The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A065849 Let u be any string of n digits from {0,...,7}; 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, 3, 11, 23, 113, 425, 1912, 11872, 57918, 303157, 1757094 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS EXAMPLE a(2)=2 because 15 and 51 (written in base 8) are primes (13 and 41). a(3)=3 because 531, 351 and 513 (in base 8) are primes (107, 233, 331), or 145, 415 and 541 (in base 8) are primes (101, 269, 353), or 147, 417 and 471 are primes (103, 271, 313) etc. R. J. Mathar, Apr 23 2016 MATHEMATICA c[x_] := Module[{},    Length[Select[Permutations[x],      First[#] != 0 && PrimeQ[FromDigits[#, 8]] &]]]; A065849[n_] := Module[{i},    Return[Max[Map[c, DeleteDuplicatesBy[Tuples[Range[0, 7], n],        Table[Count[#, i], {i, 0, 7}] &]]]]]; Table[A065849[n], {n, 1, 7}] (* Robert Price, Mar 30 2019 *) CROSSREFS Cf. A065843, A065844, A065845, A065846, A065847, A065848, A065850, A065851, A065852, A065853 Sequence in context: A074496 A292817 A292112 * A136402 A137811 A041955 Adjacent sequences:  A065846 A065847 A065848 * A065850 A065851 A065852 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified January 17 14:57 EST 2020. Contains 330958 sequences. (Running on oeis4.)