A355485 Primes p such that neither g-1 nor g+1 is prime, where g is the gap from p to the next prime.

1327, 2477, 3137, 5531, 8467, 9973, 11213, 11743, 12011, 12163, 12347, 14897, 16007, 16493, 16703, 17257, 19087, 20297, 20443, 21433, 24443, 26267, 26513, 29033, 29501, 29683, 31193, 31907, 32653, 32843, 34549, 34781, 35543, 35771, 36161, 36497, 36947, 37061, 37747, 38993, 39581, 40361, 40433

Offset

1,1

Comments

Primes prime(i) where A001223(i) is in A061673.

Links

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

Example

a(3) = 3137 is a term because 3137 is prime, the next prime is 3163 = 3137+26, and neither 26-1 = 25 nor 26+1 = 27 is prime.

Maple

q:= 2:
count:= 0:
R:= NULL:
while count < 100 do
  p:= q;
  q:= nextprime(q);
  g:= q-p;
  if not(isprime(g-1) or isprime(g+1)) then
     count:= count+1;
     R:= R, p
  fi
od:
R;

Prog

(PARI) isok(p) = if (isprime(p), my(g=nextprime(p+1)-p); !isprime(g-1) && !isprime(g+1)); \\ Michel Marcus, Jul 05 2022

Crossrefs

Cf. A001223, A061673.

Sequence in context: A202374 A259415 A015162 * A075037 A134116 A122390

Adjacent sequences: A355482 A355483 A355484 * A355486 A355487 A355488

Keyword

nonn

Author

J. M. Bergot and Robert Israel, Jul 04 2022

Status

approved