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A274700
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Numbers n such that 7*10^n + 37 is prime.
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1
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OFFSET
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1,2
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COMMENTS
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All terms are odd because 7*(9*11+1)^n + 37 is divisible by 11.
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LINKS
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EXAMPLE
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1 is in this sequence because 7*10 + 37 = 107 is prime.
3 is not in the sequence because 7*10^3 + 37 = 31*227.
Initial terms and associated primes:
a(1) = 1: 107;
a(2) = 7: 70000037;
a(3) = 15: 7000000000000037;
a(4) = 21: 7000000000000000000037, etc.
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MATHEMATICA
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Select[Range[0, 3000], PrimeQ[7 10^# + 37] &]
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PROG
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(Magma) [n: n in [1..400] | IsPrime(7*10^n+37)];
(PARI) lista(nn) = for(n=1, nn, if(ispseudoprime(7*10^n+37), print1(n, ", "))); \\ Altug Alkan, Jul 05 2016
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CROSSREFS
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Cf. similar sequences listed in A274676.
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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