A025018 Numbers k such that least prime in the Goldbach partition of k increases.

4, 6, 12, 30, 98, 220, 308, 556, 992, 2642, 5372, 7426, 43532, 54244, 63274, 113672, 128168, 194428, 194470, 413572, 503222, 1077422, 3526958, 3807404, 10759922, 24106882, 27789878, 37998938, 60119912, 113632822, 187852862, 335070838

Offset: 1

Author

David W. Wilson

Keywords

• nonn
• nice

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..69 (from Tomás Oliveira e Silva)
• Mark A. Herkommer, Goldbach Conjecture Research
• Jorg Richstein, Verifying Goldbach's Conjecture up to 4 * 10^14, Math. of Computation, Vol. 70, No. 236, pp. 1745-1749 (July 2000)
• Index entries for sequences related to Goldbach conjecture
• Tomás Oliveira e Silva, Goldbach conjecture verification

Crossrefs

Cf. A001172, A025019.

Programs

Mathematica

p = 1; r = {}; Do[ k = 2; While[ !PrimeQ[k] || !PrimeQ[2n - k], k++ ]; If[k > p, p = k; r = Append[r, 2n]], {n, 2, 10^8}]; r

PARI

Gold(n)=forprime(p=2,min(n\2,default(primelimit)),if(isprime(n-p),return(p)))
r=0;forstep(n=4,1e6,2,t=Gold(n);if(t>r,r=t;print1(n", "))) \\ Charles R Greathouse IV, Feb 21 2012

Extensions

Edited and extended by Robert G. Wilson v, Dec 13 2002