Do repeated convergences in the prime-gap sequence contain predictive information about future primes?
问题内容
Let $p_n$ be the $n$-th prime and let
$$ g_n = p_n-p_{n-1}. $$
Define
$$ S_n=\sum_{i=2}^{n} g_i=p_n-2 $$
and
$$ V_n=S_n+g_n=p_n+g_n-2. $$
I call a convergence the occurrence of the same value $V$ at two or more distinct positions.
For example, for $V=103$:
$$ 95+8=103,\qquad 99+4=103,\qquad 101+2=103. $$
Thus the associated gap sequence is
$$ (8,4,2). $$
A convergence can also produce a composite value. For example,
$$ 395+8=403,\qquad 399+4=403, $$
while
$$ 403=13\cdot31. $$
I therefore do not interpret convergence itself as a proof of primality. Instead, I performed a chronological out-of-sample computational experiment in which candidate announcements were fixed before their future primality labels were evaluated.
In the future block there were 1,536,434 announcements, of which 171,556 were prime (11.165855481%). A matched control contained 152,384 primes (9.918030973%).
The difference was 1.247824508 percentage points, with a one-sided paired permutation $p$-value of 0.00009999.
The mathematical question I would like to ask is:
Is there a known number-theoretic explanation for why repeated values of
$$ V_n=p_n+g_n-2 $$
could produce this kind of out-of-sample enrichment in future primality?
In particular,
$$ V_n=V_{n+1}\iff g_n=2g_{n+1}, $$
which produces structures such as
$$ (8,4,2),\qquad (16,8,4,2),\ldots $$
I am interested in whether these configurations, or the associated omitted composite positions, have a known interpretation in terms of prime constellations, congruence restrictions, or sieve methods.
The complete manuscript, computational code and reproducibility material are available here:
https://doi.org/10.5281/zenodo.21970844
I would particularly welcome attempts to refute the observed effect or derive a mathematical explanation for it.
回答 (1)
The possible remainders when you divide $(p_{n-1},p_n,g_n,V_n)$ by $3$ are
$$(1,1,0,2)\\(1,2,1,1)\\(2,1,2,1)\\(2,2,0,0)$$ So $V_n$ has a one in $4$ chance of being a multiple of $3$. That makes it more likely to be prime than similar numbers of the same size.