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.

A372303 Primes p such that there exists prime q < p for which p*q^2 + 1 is divisible by q^2 + p and 1 + p.

Original entry on oeis.org

7, 11, 23, 31, 41, 47, 59, 71, 79, 131, 137, 151, 167, 239, 311, 359, 443, 461, 701, 839, 911, 1021, 1039, 1367, 1721, 1847, 2207, 2351, 2551, 2861, 3191, 3719, 4019, 4691, 4759, 5039, 5167, 5279, 6971, 7481, 7853, 7919, 9311, 9619, 9689, 10607, 10739, 11447
Offset: 1

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Author

Stephen Bartell, May 22 2024

Keywords

Examples

			For n=4, a(4)=31 and q=17 satisfy the desired divisibilities.
		

Programs

  • Maple
    P:= select(isprime,[2,seq(i,i=3..100000,2)]):
    nP:= nops(P);
    R:= NULL:
    for i from 2 to nP do
      p:= P[i];
      for j from 1 to i-1 do
        q:= P[j];
        if p*q^2 + 1 mod ilcm(p+1, q^2+p) = 0 then
          R:= R,p;
          break
        fi
    od od:
    R;