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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
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).
FORMULA
a(n) = A061421(n) - A100359(n).
EXAMPLE
65 = 2^6 + 1 is a 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
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Jan 28 2016
STATUS
approved