GPT 6 Astra Ultra attempt on Math-786
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Erdős Problem #374: independent continuation
Date: 2026-09-23. Research attempt; no claim of a new published result.1) TARGET AND SOURCE AUDIT
Let $F(m)$ be the least number of distinct factorials, including $m!$, whose product is a square, and $D_k=\{m:F(m)=k\}$. Determine their growth for $3\le k\le6$, especially whether $D_6(X)\gg X$.All supplied versions considered: 374.tex. The source enlarges fixed-prime semiprime families and obtains an unbounded multiple of $X/\log X$. I show why even complete success on every semiprime cannot yield the requested positive density.
2) WORK
An elementary density barrier.
Let $\mathcal P_y$ be the primes at most $y$, and write $w_y(n)=\#\{p\in\mathcal P_y:p\mid n\}$. Every semiprime $n=pq$ has $w_y(n)\le2$. Pointwise, \[ \mathbf1_{w_y(n)\le2}\le e^2e^{-w_y(n)}. \] The right-hand side is periodic modulo $\prod_{p\le y}p$. By CRT its mean is \[ e^2\prod_{p\le y}\left(1-{1-e^{-1}\over p}\right). \] As $y\to\infty$ this tends to zero, using the divergence of $\sum_p1/p$ and $1-u\le e^{-u}$. For every fixed $y$ it bounds the upper density of all semiprimes. Therefore the semiprimes have natural density zero.The same proof works for integers with at most any fixed number $r$ of distinct prime factors, replacing $e^2$ by $e^r$. Thus no construction restricted to a fixed bound on the number of prime factors can establish $D_6(X)\gg X$, even if it settles every integer in its selected class. This is stronger than simply observing that one fixed semiprime family has size about $X/\log X$.
3) ADVERSARIAL VERIFICATION
The auxiliary parameter $y$ is fixed before taking the density limit; only afterward is it sent to infinity. This avoids any unjustified uniform error estimate. The result is a barrier for restricted constructions, not an upper bound on $D_6$ itself. The square-product identity only proves $F(m)\le6$; excluding smaller representations is a separate requirement.4) FINAL
UNRESOLVED. Positive-density membership in $D_6$, and the requested orders for the other $D_k$, remain unproved. One needs families with unbounded prime-factor complexity together with control of minimal representation length.5) SOURCES CHECKED
Full374.tex read. Indexed official statement https://www.erdosproblems.com/374 checked on 2026-09-23; the absent GitHub formalization was not used. The source's imported Erdős--Graham semiprime theorem is not required by the density-barrier proof.