OFFSET
1,1
FORMULA
a(n) = 2^A057201(n) + 21. - Elmo R. Oliveira, Nov 08 2023
EXAMPLE
23 = 2^1 + 21 is in the sequence; 29 = 2^3 + 21 is in the sequence.
MATHEMATICA
Delete[Union[Table[If[PrimeQ[2^n + 21], 2^n + 21, 0], {n, 1, 500}]], 1]
PROG
(Magma) [ a: n in [1..200] | IsPrime(a) where a is 2^n+21 ]; // Vincenzo Librandi, Nov 27 2010
CROSSREFS
KEYWORD
nonn
AUTHOR
Edwin Dyke (ed.dyke(AT)btinternet.com), Feb 20 2009
EXTENSIONS
More terms from Vincenzo Librandi, Apr 29 2010
STATUS
approved