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A321582 Primes p such that (4*p+1)/5 is prime. 2
241, 421, 541, 571, 751, 1171, 1291, 1621, 1861, 2011, 2221, 2251, 2341, 2521, 2671, 2851, 2971, 3271, 3361, 3391, 3541, 3571, 3691, 4021, 4201, 4591, 4621, 4861, 5641, 5701, 5821, 6211, 6961, 7321, 7351, 7591, 7951, 8101, 8161, 8191, 8221, 8821, 8971, 9151, 9241, 9421 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Subsequence of A320774.

LINKS

Seiichi Manyama, Table of n, a(n) for n = 1..10000

EXAMPLE

241 is a term since it is prime and (4*241+1)/5 = 193, prime.

MAPLE

for n from 4 to 1000 do

Y := ithprime(n);

Z := 4*Y+1;

K := (1/5)*Z;

if mod(Z, 5) = 0 and isprime(K) then print(Y);

end if:

end do:

MATHEMATICA

Select[Prime[Range[1000]], PrimeQ[(4 # + 1)/5] &] (* Amiram Eldar, Nov 13 2018 *)

CROSSREFS

Cf. A320774.

Sequence in context: A139502 A140629 A325088 * A137771 A108831 A068706

Adjacent sequences:  A321579 A321580 A321581 * A321583 A321584 A321585

KEYWORD

nonn

AUTHOR

David James Sycamore, Nov 13 2018

EXTENSIONS

More terms from Seiichi Manyama, Dec 24 2018

STATUS

approved

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Last modified August 18 01:19 EDT 2019. Contains 326059 sequences. (Running on oeis4.)