OFFSET
1,1
COMMENTS
No further terms up to 10^5.
EXAMPLE
Both 10 = 3+7 = 5+5 and 20 = 3+17 = 7+13 have two Goldbach partitions, so 5 is a term.
MAPLE
N:= 100000: # to test k <= N
P:= select(isprime, [2, seq(i, i=3..4*N-2, 2)]):
G:= Vector(4*N):
for i from 1 to nops(P) do
jmax:= ListTools:-BinaryPlace(P, 4*N-P[i]);
if jmax < i then break fi;
J:= P[i..jmax]+~ P[i];
G[J]:= G[J] +~ 1
od:
select(t -> G[2*t] = G[4*t], [$1..N]); # Robert Israel, Sep 02 2024
MATHEMATICA
f[n_]:=Length[Select[2*n-Prime[Range[PrimePi[n]]], PrimeQ]];
Select[Range[250], f[#]==f[2*#]&]
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Ivan N. Ianakiev, Sep 01 2024
STATUS
approved