A352630 First of two consecutive primes p,q such that either p+2*q and (2*p+q)/5 or (p+2*q)/5 and 2*p+q are primes.

7, 11, 17, 19, 101, 109, 227, 229, 277, 349, 521, 743, 769, 839, 937, 983, 1151, 1373, 1427, 1609, 1721, 1823, 2039, 2081, 2267, 2273, 2843, 3373, 3433, 3779, 3821, 3847, 3967, 4217, 4517, 4583, 5417, 5531, 5669, 5779, 6197, 6577, 6701, 6761, 6883, 7537, 7669, 7727, 8467, 8609, 8837, 9173, 9281

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

a(3) = 17 is a term because it is prime, the next prime is 19, and (17+2*19)/5 = 11 and 2*17+19 = 53 are prime.

Maple

R:= NULL: q:= 2:
while q < 10000 do
  p:= q; q:= nextprime(p); s:= p+2*q; t:= 2*p+q;
  if (s mod 5 = 0 and isprime(s/5) and isprime(t)) or (t mod 5 = 0 and isprime(s) and isprime(t/5)) then R:= R, p;
  fi
od:
R;

Crossrefs

Cf. A181848.

Sequence in context: A309587 A339954 A260893 * A360396 A299978 A131229

Adjacent sequences: A352627 A352628 A352629 * A352631 A352632 A352633

Keyword

nonn

Author

J. M. Bergot and Robert Israel, Mar 24 2022

Status

approved