login
A335250
Numbers m such that twice the number of unordered Goldbach partitions of 2m equals the number of unordered Goldbach partitions of 4m.
1
1, 4, 9, 15, 21, 30, 40, 46, 69, 70, 79, 81, 82, 106, 114, 199, 229, 256, 361, 391, 469, 586, 754, 760, 766, 826, 892, 1471, 1483, 1525, 1591, 1609, 1624, 1816, 2194, 2206, 2454, 2629, 2869, 3955, 3961, 3964, 6406, 6946, 11749
OFFSET
1,2
COMMENTS
Integers m such that 2*A002375(2m) = A002375(4m).
It is conjectured that the last term in this sequence is a(45)=11749.
EXAMPLE
m=4 is a term because 2m=8 has the partition (3,5) while 4m=16 has the partitions (3,13) and (5,11).
PROG
(PARI) for(n=1, 200000, x=0; y=0; forprime(i=2, 2*n-1, if(i<=n && isprime(2*n-i), x=x+1; ); if(isprime(4*n-i), y=y+1; ); ); if(2*x==y, print1(n, ", ")))
CROSSREFS
Sequence in context: A358243 A099055 A162801 * A103396 A103400 A103399
KEYWORD
nonn,more
AUTHOR
Craig J. Beisel, May 28 2020
STATUS
approved