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Search: id:A129962
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| A129962 |
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Primes of the form 2^n + n. |
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+0
1
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| 3, 11, 37, 521, 32783, 549755813927, 37778931862957161709643, 2417851639229258349412433, 618970019642690137449562201, 26699837949011376029937771327119401432533806529458159624338020097777746572258006\ 8752870260867389
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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It is convenient, although not necessary, to let n be an odd number since n even => 2^n + n is even > 2. Conjecture: There is an infinite number of primes in this sequence. If n is prime we have A057664.
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EXAMPLE
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for n = 3, 2^3+3=11 prime and the second entry.
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PROGRAM
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(PARI) f(n) = forstep(x=1, n, 2, y=2^x+x; if(isprime(y), print1(y", ")))
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CROSSREFS
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Cf. A057664.
Sequence in context: A046722 A047102 A109000 this_sequence A026361 A006189 A092201
Adjacent sequences: A129959 A129960 A129961 this_sequence A129963 A129964 A129965
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KEYWORD
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nonn
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AUTHOR
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Cino Hilliard (hillcino368(AT)hotmail.com), Jun 10 2007
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