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A248409 Least prime of the form x^2+13*n^2. 1
13, 53, 181, 233, 389, 757, 641, 857, 1069, 1301, 1609, 1873, 2213, 2549, 3121, 3329, 3761, 4261, 4729, 5209, 5737, 6301, 6977, 7489, 8161, 8837, 9733, 10193, 10937, 11701, 12497, 13313, 14173, 15053, 16069, 17137, 18121, 18773, 19777, 20809, 21997, 23053, 24137, 25169, 27109, 27509 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Subsequence of A033210 (Primes of the form x^2+13*y^2).
LINKS
EXAMPLE
a(1)=13 because the least prime of the form x^2+13*1^2 is 13 (at x=0).
a(100)=130121 because the least prime of the form x^2+13*100^2 is 130121 (at x=11).
a(200)=520361 because the least prime of the form x^2+13*200^2 is 520361 (at x=19).
PROG
(PARI) a(n) = {x = 0; while (!isprime(p=x^2+13*n^2), x++); p; } \\ Michel Marcus, Oct 06 2014
CROSSREFS
Sequence in context: A179549 A139974 A142188 * A206444 A156156 A201486
KEYWORD
nonn
AUTHOR
Zak Seidov, Oct 06 2014
STATUS
approved

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Last modified February 23 00:26 EST 2024. Contains 370265 sequences. (Running on oeis4.)