%I #48 Feb 24 2020 04:22:57
%S 8,46,87,168,259,262,292,329,446,1056,3562,11819,26737
%N Numbers k for which (9 + k!)/9 is prime.
%C No other k exists, for k <= 6000. - Dimitris Zygiridis (dmzyg70(AT)gmail.com), Jul 25 2008
%C The next number in the sequence, if one exists, is greater than 10944. - _Robert Price_, Mar 16 2010
%C Borrowing from A139074 another term in this sequence is 26737. There may be others between 10944 and 26737. - _Robert Price_, Dec 13 2011
%C There are no other terms for k < 26738. - _Robert Price_, Feb 10 2012
%e a(11) = 3562 because 3562 is the 11th natural number for which k!/9 + 1 is prime. 3562 is the new term.
%t a = {}; Do[If[PrimeQ[(n! + 9)/9], AppendTo[a, n]], {n, 1, 500}]; a
%o (PARI) for(n=6,1e4,if(ispseudoprime(n!/9+1),print1(n", "))) \\ _Charles R Greathouse IV_, Jul 15 2011
%o (PFGW) ABC2 $a!/9+1
%o a: from 6 to 1000 // _Jinyuan Wang_, Feb 04 2020
%Y Cf. A139068 (primes of the form (9 + k!)/9).
%Y Cf. k!/m - 1 is a prime: A002982, A082671, A139056, A139199-A139205.
%Y Cf. (m + k!)/m is a prime: A002981, A082672, A089085, A139061, A139058, A139063, A139065, A151913, A139071.
%K nonn,more
%O 1,1
%A _Artur Jasinski_, Apr 09 2008
%E Edited by _N. J. A. Sloane_, May 15 2008 at the suggestion of _R. J. Mathar_
%E a(10) corrected from 1053 to 1056 by _Dmitry Kamenetsky_, Jul 12 2008
%E a(11) from Dimitris Zygiridis (dmzyg70(AT)gmail.com), Jul 25 2008
%E a(12)-a(13) from _Robert Price_, Feb 10 2012