# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a037034 Showing 1-1 of 1 %I A037034 #7 May 18 2013 16:49:19 %S A037034 1,1,1,2,1,1,3,1,2,2,1,1,2,3,1,2,1,1,2,1,1,3,4,2,2,1,1,2,3,2,5,1,1,2, %T A037034 1,3,3,1,2,3,1,1,5,7,1,2,3,1,3,1,5,5,1,2,2,1,1,2,13,1,2,3,1,5,4,1,6,1, %U A037034 3,3,1,3,5,3,2,2,1,1,2,4,2,3,1,7,3,3,1,5,4,1,2,1,2,2,1,1,3,4,3,5,6,3,2,4 %N A037034 Least k such that 4*n*k-1 is a prime. %H A037034 Harvey P. Dale, Table of n, a(n) for n = 1..1000 %e A037034 a(5)=1 because 4*5*1-1=19 is a prime %t A037034 lk[n_]:=Module[{c=4n,k=1},While[!PrimeQ[c*k-1],k++];k]; Array[lk,110] (* _Harvey P. Dale_, Jun 05 2012 *) %Y A037034 Cf. A016014. %K A037034 nonn %O A037034 1,4 %A A037034 _Felice Russo_ %E A037034 More terms from _Erich Friedman_ # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE