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A215233 Primes of the form 4m^2 + 1 such that the next prime of this form is a record distance away. 2
5, 37, 677, 1601, 8837, 33857, 122501, 246017, 11492101, 12503297, 2058436901, 6844914757, 9813676097, 127566122897, 707119537217, 15058714869137, 779243651884097, 1641669426950401, 10965274367622437, 1269017804759665217, 4346851918104880901 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Distance from 4m^2+1 to 4n^2+1 is measured as n-m.

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..26

PROG

(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

CROSSREFS

See A215234 for the next larger prime of the form 4m^2 + 1.

Cf. A214518 (record differences of m), A214519 (values of m).

Sequence in context: A095957 A354862 A121834 * A083846 A336241 A180275

Adjacent sequences:  A215230 A215231 A215232 * A215234 A215235 A215236

KEYWORD

nonn,hard

AUTHOR

T. D. Noe, Aug 14 2012

EXTENSIONS

a(19)-a(21) from Charles R Greathouse IV, Apr 09 2013

STATUS

approved

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Last modified August 12 23:52 EDT 2022. Contains 356077 sequences. (Running on oeis4.)