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A338771 Primes p such that A338770(p) is prime. 1
7, 41, 59, 61, 89, 167, 193, 251, 257, 283, 367, 401, 479, 523, 599, 601, 641, 743, 761, 811, 983, 997, 1087, 1109, 1117, 1201, 1277, 1361, 1429, 1483, 1619, 1741, 1789, 1861, 1889, 1901, 1931, 2237, 2297, 2417, 2609, 2843, 2897, 2939, 2971, 3023, 3121, 3167, 3373, 3413, 3457, 3533, 3719, 3767 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..3790

EXAMPLE

a(3)=59 is in the sequence because 59 is prime and A338770(59) = 103 is prime.

MAPLE

filter:= proc(p) local q, v, t;

     t:= 0; q:= 1;

     do

       q:= nextprime(q);

       if 2*q > p then return isprime(t) fi;

       v:= p-2*q;

       if isprime(v) then t:= t+v fi;

     od

end proc:

select(filter, [seq(ithprime(i), i=1..2000)]);

PROG

(PARI) f(n) = my(s=0); forprime(p=0, n\2, if (isprime(q=n-2*p), s+=q)); s; \\ A338770

isok(p) = isprime(p) && isprime(f(p)); \\ Michel Marcus, Nov 08 2020

CROSSREFS

Cf. A338770.

Sequence in context: A080666 A224718 A272387 * A161505 A105902 A031909

Adjacent sequences:  A338768 A338769 A338770 * A338772 A338773 A338774

KEYWORD

nonn

AUTHOR

J. M. Bergot and Robert Israel, Nov 08 2020

STATUS

approved

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Last modified December 4 13:03 EST 2021. Contains 349526 sequences. (Running on oeis4.)