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A357056 Integers k such that k^k + k^2 + 2*k + 1 is prime. 0
0, 1, 2, 3, 4, 9, 10, 13, 15, 24 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
The next prime (if any) is unknown, but it must exceed 2000^2000 + 2000^2 + 2*2000 + 1 (a 6603-digit number).
LINKS
EXAMPLE
If k = 2, then k^k + k^2 + k*2 + 1 = 2^2 + 2^2 + 2*2 + 1 = 13, which is prime.
CROSSREFS
Sequence in context: A073338 A200260 A190119 * A273907 A066105 A083180
KEYWORD
nonn,more,hard
AUTHOR
Marco Ripà, Sep 10 2022
STATUS
approved

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Last modified April 19 07:11 EDT 2024. Contains 371782 sequences. (Running on oeis4.)