%I #11 Feb 07 2014 10:54:28
%S 1,1,1,1,1,2,3,11,2,4,1,2,3,15,23,6,11,1,7,6,7,10,1,9,28,1,3,7,63,1,
%T 25,29,13,3,25,12,9,18,20,15,66,3,5,39,10,37,15,14,31,6,9,27,12,7,15,
%U 12,6,11,41,35,116,15,7,28,6,9,23,28,23,2,2,9,5,17,27,56,69,132,29,1,20,17
%N Smallest k>0 such that (2^k)*A002110(n) + 1 is prime.
%H Pierre CAMI, <a href="/A098929/b098929.txt">Table of n, a(n) for n = 1..1029</a>
%t f[n_] := Block[{k = 1, p = Product[Prime[i], {i, n}]}, While[ !PrimeQ[2^k*p + 1], k++ ]; k]; Table[ f[n], {n, 82}]
%o (PFGW & SCRIPT)
%o Command pfgw64 -f in.txt
%o in.txt = SCRIPT file
%o SCRIPT
%o DIM n,0
%o DIM i,0
%o DIM pp
%o DIMS t
%o OPENFILEOUT myf,a(n).txt
%o LABEL loop1
%o SET n,n+1
%o SET i,0
%o LABEL loop2
%o SET i,i+1
%o SETS t,%d,%d,%d\,;n;p(n);i
%o SET pp,(2^i)*p(n)#+1
%o PRP pp,t
%o IF ISPRP THEN GOTO a
%o GOTO loop2
%o LABEL a
%o WRITE myf,t
%o GOTO loop1
%Y Cf. A002110, A097099.
%K nonn
%O 1,6
%A _Pierre CAMI_ and _Robert G. Wilson v_, Sep 27 2004
|