OFFSET
1,1
COMMENTS
This sequence is analogous to the sequence formed by the Goldbach-Euler conjecture that every even number greater than 2 is the sum of 2 primes. If p + 2 is prime then p and p + 2 are twin primes. The number of terms in this sequence is infinite. This follows immediately from the proof that the number of primes p is infinite. Conjecture: The ratio of the number of terms in this sequence to Pi(n) tends to a limit < 1.
The first term in this sequence that is not also in A062721 is 45 = 3^2 * 5. - Alonso del Arte, May 03 2014
FORMULA
a(n) = A067774(n) + 2. - Amiram Eldar, Jul 05 2024
MATHEMATICA
Select[Range[4, 399], Not[PrimeQ[#]] && PrimeQ[# - 2] &] (* Alonso del Arte, May 03 2014 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Cino Hilliard, Jun 13 2005
STATUS
approved