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 A268211 Numbers n of the form 2^k + 1 such that n + k is a prime q (for k >= 0). 1
 2, 5, 65, 110427941548649020598956093796432407239217743554726184882600387580788737 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Subsequence of A000051. Corresponding values of numbers k are in A100359 (numbers n such that 2^n+n+1 is prime). Corresponding values of primes q are in A061421 (primes of the form 2^n+n+1). LINKS FORMULA a(n) = A061421(n) - A100359(n). EXAMPLE 65 = 2^6 + 1 is term because 65 + 6 = 71 (prime). MATHEMATICA 2^# + 1 &@ Select[Range[0, 600], PrimeQ[2^# + # + 1] &] (* Michael De Vlieger, Jan 29 2016 *) PROG (MAGMA) [2^n + 1: n in [0..600] | IsPrime(2^n + n + 1)] CROSSREFS Cf. A061421, A100359, A268209. Sequence in context: A270389 A086560 A305292 * A246280 A333165 A133004 Adjacent sequences:  A268208 A268209 A268210 * A268212 A268213 A268214 KEYWORD nonn AUTHOR Jaroslav Krizek, Jan 28 2016 STATUS approved

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Last modified September 17 14:07 EDT 2021. Contains 347478 sequences. (Running on oeis4.)