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A057909 Numbers k such that 4^k + k is prime. 0
1, 3, 9, 15, 37, 85, 133, 225, 1233, 12793 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(11) > 20000. - Jinyuan Wang, Feb 01 2020

LINKS

Table of n, a(n) for n=1..10.

MATHEMATICA

Do[ If[ PrimeQ[ 4^n + n ], Print[ n ] ], {n, 0, 3000} ]

PROG

(PARI) is(n)=ispseudoprime(4^n+n) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Cf. A052007, A057900.

Cf. A158879 (4^n + n).

Sequence in context: A058039 A013581 A133997 * A228916 A345431 A082702

Adjacent sequences:  A057906 A057907 A057908 * A057910 A057911 A057912

KEYWORD

nonn,more

AUTHOR

Robert G. Wilson v, Nov 16 2000

EXTENSIONS

a(10) from Jinyuan Wang, Feb 01 2020

STATUS

approved

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Last modified July 23 16:03 EDT 2021. Contains 346259 sequences. (Running on oeis4.)