cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A341215 Primes p such that 2*p+3*q and 3*p+2*q are prime, where q is the next prime after p.

Original entry on oeis.org

5, 7, 11, 19, 29, 31, 37, 43, 53, 113, 127, 163, 173, 199, 257, 271, 317, 353, 397, 439, 457, 461, 557, 599, 659, 757, 809, 991, 997, 1019, 1069, 1129, 1289, 1327, 1439, 1447, 1549, 1621, 1733, 1747, 1759, 1831, 1913, 2027, 2113, 2141, 2153, 2309, 2339, 2357, 2383, 2423, 2473, 2663, 2741, 2801
Offset: 1

Views

Author

J. M. Bergot and Robert Israel, Feb 06 2021

Keywords

Examples

			a(3) = 11 is a term because the next prime is 13 and 2*11+3*13 = 61 and 3*11+2*13 = 59 are prime.
		

Crossrefs

Contains A174922.

Programs

  • Maple
    R:=  NULL: count:= 0:
    q:= 2:
    while count < 100 do
      p:= q; q:= nextprime(p);
      if isprime(2*p+3*q) and isprime(3*p+2*q) then
        count:= count+1; R:= R, p
      fi
    od:
    R;
  • Mathematica
    Select[Partition[Prime[Range[500]],2,1],AllTrue[{2#[[1]]+3#[[2]],3#[[1]]+2#[[2]]},PrimeQ]&][[;;,1]] (* Harvey P. Dale, Jun 11 2025 *)
  • PARI
    isok(p) = isprime(p) && (q=nextprime(p+1)) && isprime(2*p+3*q) && isprime(3*p+2*q); \\ Michel Marcus, Feb 07 2021