OFFSET
1,3
COMMENTS
If A084435 ever hits a Sierpinski number, the sequence is finite.
a(18) > 10^6. - Harsh R. Aggarwal, Sep 14 2024
LINKS
Eric Weisstein's World of Mathematics, Sierpinski Number of the Second Kind.
PROG
(PARI) a=2; for(x=1, 16, for(k=0, 1000000, p=2^k*a+1; if(isprime(p), print(k); break)); a=p)
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Ken Takusagawa, Jan 19 2006
EXTENSIONS
a(16)-a(17) from Harsh R. Aggarwal, Apr 11 2018
STATUS
approved