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A215233
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Primes of the form 4m^2 + 1 such that the next prime of this form is a record distance away.
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2
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5, 37, 677, 1601, 8837, 33857, 122501, 246017, 11492101, 12503297, 2058436901, 6844914757, 9813676097, 127566122897, 707119537217, 15058714869137, 779243651884097, 1641669426950401, 10965274367622437, 1269017804759665217, 4346851918104880901
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OFFSET
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1,1
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COMMENTS
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Distance from 4m^2+1 to 4n^2+1 is measured as n-m.
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LINKS
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PROG
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(PARI) r=0; last=2; forstep(n=4, 1e9, 2, if(!ispseudoprime(n^2+1), next); if(n-last>r, r=n-last; print1(last^2+1", ")); last=n) \\ Charles R Greathouse IV, Apr 09 2013
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CROSSREFS
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See A215234 for the next larger prime of the form 4m^2 + 1.
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KEYWORD
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nonn,hard
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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