A132358 a(n) = greatest prime <= 2^(2^n).

2, 3, 13, 251, 65521, 4294967291, 18446744073709551557, 340282366920938463463374607431768211297, 115792089237316195423570985008687907853269984665640564039457584007913129639747

Offset: 0

Author

Leroy Quet, Nov 08 2007

Keywords

• nonn

Crossrefs

Cf. A132198.

Programs

Mathematica

a={}; For[n=0, n<10, n++, b=2^(2^n); While[ !PrimeQ[b], b=b-1]; AppendTo[a, b]]; a (* Stefan Steinerberger, Nov 12 2007 *)
If[PrimeQ[#],#,NextPrime[#,-1]]&/@(2^(2^Range[0,10])) (* Harvey P. Dale, Jul 01 2020 *)

Extensions

More terms from Stefan Steinerberger, Nov 12 2007