This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A089085 #31 Sep 08 2022 08:45:12 %S A089085 3,5,6,8,11,17,23,36,77,93,94,109,304,497,1330,1996,3027,3053,4529, %T A089085 5841,20556,26558,28167 %N A089085 Numbers k such that (k! + 3)/3 is prime. %C A089085 a(21) > 20000. The PFGW program has been used to certify all the terms up to a(20), using the "N-1" deterministic test. - _Giovanni Resta_, Mar 31 2014 %t A089085 Select[Range[0, 1400], PrimeQ[(#!+3)/3] &] (* _Vladimir Joseph Stephan Orlovsky_, Apr 29 2008 *) %o A089085 (Magma) [n: n in [0..500] | IsPrime((Factorial(n)+3) div 3)]; // _Vincenzo Librandi_, Dec 12 2011 %o A089085 (PARI) is(n)=ispseudoprime(n!\3+1) \\ _Charles R Greathouse IV_, Mar 21 2013 %Y A089085 Cf. A089131. %Y A089085 Cf. n!/m-1 is a prime: A002982, A082671, A139056, A139199-A139205; n!/m+1 is a prime: A002981, A082672, A089085, A139061, A139058, A139063, A139065, A151913, A137390, A139071 (1<=m<=10). %K A089085 nonn %O A089085 1,1 %A A089085 _Cino Hilliard_, Dec 05 2003 %E A089085 More terms from _Don Reble_, Dec 06 2003 %E A089085 1330 from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 03 2008 %E A089085 Typo in Mma program corrected by _Vincenzo Librandi_, Dec 12 2011 %E A089085 a(16)-a(20) from _Giovanni Resta_, Mar 31 2014 %E A089085 a(21)-a(23) from _Serge Batalov_, Feb 17 2015