A123370 Primes of the form (2^n + 7)/3.

3, 5, 13, 173, 699053, 3301173438094347399730997933, 15589350798196297794172638215640352209663280458413

Offset: 1

Author

Zak Seidov, Oct 12 2006

Keywords

• nonn

Comments

Corresponding n's are 1,3,5,9,21,93 (all but n=3 are of the form n=4m+1, m=0,1,2,5,23...). Cf. A123250 = primes of the form 2^n + 5.

Crossrefs

Cf. A123250.

Programs

Mathematica

Select[(2^Range[0,1000]+7)/3,PrimeQ] (* Harvey P. Dale, May 20 2013 *)

Extensions

a(7) from Harvey P. Dale, May 20 2013