This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
lst={};Do[p=Prime[n];If[PrimeQ[p=p+2^p],AppendTo[lst,p]],{n,5!}];lst (* Vladimir Joseph Stephan Orlovsky, Jan 28 2009 *)
Select[#+2^#&/@Prime[Range[100]],PrimeQ] (* Harvey P. Dale, Feb 19 2018 *)
p=3 is prime, and so is 2^p - p = 8 - 3 = 5, so 5 is in the sequence. - _Michael B. Porter_, Jul 19 2016
a:=proc(n) if isprime(2^ithprime(n)-ithprime(n))=true then 2^ithprime(n)-ithprime(n) else fi end: seq(a(n),n=1..310); # Emeric Deutsch
lst={};Do[p=Prime[n];If[PrimeQ[p=2^p-p],AppendTo[lst,p]],{n,5!}];lst (* Vladimir Joseph Stephan Orlovsky, Jan 28 2009 *)
Select[Table[2^p-p,{p,Prime[Range[20]]}],PrimeQ] (* Harvey P. Dale, Sep 20 2018 *)
Select[Range[10^3], PrimeQ[# + 2^#] &@ Prime@ # &] (* Michael De Vlieger, Oct 26 2017 *)
isok(n) = isprime(prime(n) + 2^prime(n)); \\ Michel Marcus, Dec 19 2013
p=13, 2^13 - 13 = 8179 is prime.
lista(nn) = forprime(p=2, nn, if(ispseudoprime(2^p - p), print1(p, ", ")))
6 is a term because 2*2^6 + 6/2 = 131 is prime for divisor d = 2 of k = 6.
[k: k in [1..1000] | not #[d: d in Divisors(k) | IsPrime(d*2^k+(k div d))] eq 0];
Select[Range[4300],Sum[Boole[PrimeQ[d*2^#+#/d]],{d,Divisors[#]}]>0 &] (* Stefano Spezia, May 16 2025 *)
is(n, f=factor(n))=fordiv(n>>valuation(n,2),d, if(isprime(n/d*2^n+d), return(1))); 0 \\ Charles R Greathouse IV, May 17 2025
Comments