A337815 Primes p such that p+q = r*(s+1) where q is the next prime after p, and r and s are primes.

3, 5, 7, 11, 17, 19, 29, 41, 43, 47, 59, 71, 79, 89, 97, 101, 103, 107, 109, 113, 137, 149, 151, 163, 167, 173, 179, 191, 193, 197, 211, 223, 227, 229, 239, 241, 257, 269, 281, 283, 293, 311, 313, 337, 347, 349, 359, 397, 401, 419, 421, 431, 439, 457, 461, 479, 491, 503, 521, 523, 547, 557, 569

Offset

1,1

Links

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

Example

a(3)=7 is in the sequence because 7+11=3*(5+1) where 11 is the next prime after 7, and 7, 3 and 5 are primes.

Maple

filter:= proc(t) local q, p;
  for p in numtheory:-factorset(t) do
     q:= t/p-1;
     if q > p and isprime(q) then return true fi
  od;
  false
end proc:
B:= select(filter, [seq(ithprime(i)+ithprime(i+1), i=1..1000)]):
map(t -> prevprime(t/2), B);

Crossrefs

Includes A001359.

Sequence in context: A194099 A045396 A155779 * A235476 A349638 A045397

Adjacent sequences: A337812 A337813 A337814 * A337816 A337817 A337818

Keyword

nonn

Author

J. M. Bergot and Robert Israel, Sep 23 2020

Status

approved