|
%I #16 Jul 14 2017 11:29:30
%S 2,1,1,2,3,1,3,3,5,2,9,5,7,4,3,14,8,4,4,9,11,8,3,7,9,10,2,36,3,1,4,6,
%T 4,2,17,3,7,4,6,14,17,14,51,3,9,12,38,8,13,36,64,30,14,14,4,19,13,41,
%U 5,19,4,60,8,20,3,13,24,10,31,15,14,42,19,13,1,30,11,11
%N a(n) = smallest k such that k*n*2^n-1 is prime.
%C If k = 1 then n*2^n-1 is a Woodall prime (A050918).
%H Pierre CAMI, <a href="/A288158/b288158.txt">Table of n, a(n) for n = 1..10000</a>
%t Table[k = 1; While[! PrimeQ[k n*2^n - 1], k++]; k, {n, 78}] (* _Michael De Vlieger_, Jun 07 2017 *)
%o (PARI) a(n) = my(k=1); while(1, if(ispseudoprime(k*n*2^n-1), return(k)); k++) \\ _Felix Fröhlich_, Jun 06 2017
%Y Cf. A050918.
%K nonn
%O 1,1
%A _Pierre CAMI_, Jun 06 2017
|
