OFFSET
0,1
PROG
PFGW SCRIPTIFY
SCRIPT
DIM nn, -1
DIM kk
DIMS tt
LABEL loopn
SET nn, nn+1
SET kk, 1
LABEL loopk
SET kk, kk+1
SETS tt, %d, %d, %d\,; nn; kk; p(kk)
PRP p(kk)*2^(2^nn)+1, tt
IF ISPRIME THEN GOTO loopn
IF ISPRP THEN GOTO loopn
GOTO loopk
(PARI) A187419(n)={
local(f =2^(2^n), p=3);
while(1,
if(isprime(f*p+1),
return(p)
);
p=nextprime(p+1);
) ;
} /* R. J. Mathar, Mar 11 2011 */
CROSSREFS
KEYWORD
nonn,hard
AUTHOR
Pierre CAMI, Mar 09 2011
STATUS
approved