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 A056208 Primes p+2^n arising in A056206. 10
 3, 5, 7, 11, 19, 37, 67, 131, 263, 523, 1031, 2053, 4099, 8209, 16421, 32771, 65539, 131101, 262147, 524341, 1048583, 2097169, 4194371, 8388619, 16777259, 33554473, 67108961, 134217757, 268435459, 536870923, 1073741827, 2147483659 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS Robert Israel, Table of n, a(n) for n = 0..2000 EXAMPLE n=13, 2^13+p=8192+p is not prime for p=2,3,5,7,11,13. At first, for p=17, 8209 is prime; Primes obtained also for many larger p, the next is 8221. So a(13)=8209, the smallest one. MAPLE f:= proc(n) local p, q, t;   t:= 2^n; p:= 1;   do     p:= nextprime(p);     q:= p+t;     if isprime(q) then return q fi   od end proc: map(f, [\$0..50]); # Robert Israel, Aug 22 2019 MATHEMATICA a[n_] := Module[{p = 1, q, t = 2^n}, While[True, p = NextPrime[p]; q = p+t; If[PrimeQ[q], Return[q]]]]; a /@ Range[0, 50] (* Jean-François Alcover, Jun 09 2020, after Maple *) CROSSREFS Cf. A056206. Sequence in context: A126116 A161423 A133846 * A323065 A225421 A175235 Adjacent sequences:  A056205 A056206 A056207 * A056209 A056210 A056211 KEYWORD nonn AUTHOR Labos Elemer, Oct 06 2000 EXTENSIONS a(0)=3 inserted by Robert Israel, Aug 22 2019 STATUS approved

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Last modified September 27 17:05 EDT 2021. Contains 347693 sequences. (Running on oeis4.)