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A129962
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Primes of the form 2^k + k.
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7
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3, 11, 37, 521, 32783, 549755813927, 37778931862957161709643, 2417851639229258349412433, 618970019642690137449562201, 266998379490113760299377713271194014325338065294581596243380200977777465722580068752870260867389
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OFFSET
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1,1
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COMMENTS
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It is convenient, although not necessary, to let k be an odd number since k even => 2^k + k is even > 2.
Conjecture: sequence is infinite.
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LINKS
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EXAMPLE
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For k = 3, 2^3 + 3 = 11 prime, so 11 is a term.
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MATHEMATICA
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PROG
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(PARI) f(n) = forstep(x=1, n, 2, y=2^x+x; if(isprime(y), print1(y", ")))
(Magma) [a: n in [0..400] | IsPrime(a) where a is 2^n + n]; // Vincenzo Librandi, Jul 25 2019
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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