login
A352787
Numbers with as many divisors as Goldbach partitions.
0
34, 46, 58, 102, 116, 122, 138, 150, 154, 162, 172, 184, 190, 196, 212, 228, 264, 266, 296, 304, 332
OFFSET
1,1
COMMENTS
If it exists, a(22) > 7*10^5. - Ivan N. Ianakiev, Apr 11 2022
Numbers k such that A000005(k) = A061358(k). - Michel Marcus, Apr 12 2022
EXAMPLE
122 is in the sequence since it has 4 divisors {1,2,61,122} and 4 Goldbach partitions (13,109), (19,103), (43,79), (61,61).
MATHEMATICA
Select[Range[332], DivisorSigma[0, #]==Length[Select[#-Prime[Range[PrimePi[#/2]]], PrimeQ]]&] (* Ivan N. Ianakiev, Apr 11 2022 *)
PROG
(PARI) nbgp(n) = my(s); forprime(q=2, n\2, s+=isprime(n-q)); s; \\ A061358
isok(k) = numdiv(k) == nbgp(k); \\ Michel Marcus, Apr 12 2022
CROSSREFS
Sequence in context: A274189 A275194 A341173 * A074757 A211710 A039327
KEYWORD
nonn,more
AUTHOR
Wesley Ivan Hurt, Apr 02 2022
STATUS
approved