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.

A109885 Let n be an even integer > 2. Let PrimeP be the number of prime partition pairs {p,q} corresponding to n such that n = p + q, p and q are prime and p <= q. Let CompP be the number of composite partition pairs {r,s} corresponding to n such that n = r + s, r is prime, s is composite and r <= s. For what n's is 2*PrimeP > CompP?

Original entry on oeis.org

4, 10, 22, 24, 34, 36, 48, 54, 60, 66, 72, 78, 84, 90, 102, 114, 120, 126, 144, 150, 156, 168, 180, 186, 198, 204, 210, 240, 246, 252, 270, 294, 300, 324, 330, 360, 378, 390, 420, 450, 462, 480, 510, 540, 546, 570, 600, 630, 660, 690, 714, 720, 750, 780, 840
Offset: 1

Views

Author

Gilmar Rodriguez Pierluissi (gilmarlily(AT)yahoo.com), Aug 31 2005

Keywords

Comments

Except for a(1), a(2) a(3) & a(5), a(n)==0 (mod 6). - Robert G. Wilson v

Programs

  • Mathematica
    fQ[n_] := Block[{t = n - Prime@Range@PrimePi[n/2]}, 2Length[Select[t, PrimeQ]] > Length[t]]; Select[ 2Range[2, 434], fQ[ # ] &] (* Robert G. Wilson v, Nov 03 2005 *)

Extensions

Edited by Robert G. Wilson v, Nov 03 2005