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A249305 Primes p such that 2^p - p^2 is not squarefree. 0
2, 89, 149, 151, 383, 409, 443 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Sequence is infinite, containing all primes congruent to 2, 4, 89, or 115 mod 147. - Charles R Greathouse IV, Oct 28 2014
997 is also a term in this sequence. - Kevin P. Thompson, Jun 13 2022
LINKS
FORMULA
a(n) < (21 + e)*n log n for any e > 0 and all large enough n. - Charles R Greathouse IV, Oct 28 2014
EXAMPLE
2 is in this sequence because 2 is prime and 2^2 - 2^2 = 0 is not squarefree.
PROG
(Magma) [n: n in [3..269] | IsPrime(n) and not IsSquarefree(2^n - n^2)];
(PARI) is(n)=isprime(n) && !issquarefree(2^n-n^2) \\ Charles R Greathouse IV, Oct 28 2014
CROSSREFS
Sequence in context: A139881 A161676 A235467 * A023302 A041967 A226768
KEYWORD
nonn,more
AUTHOR
EXTENSIONS
a(5)-a(6) from Charles R Greathouse IV, Oct 28 2014
a(7) from Kevin P. Thompson, Jun 13 2022
STATUS
approved

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Last modified July 18 13:34 EDT 2024. Contains 374378 sequences. (Running on oeis4.)