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Infinitely many composites n with n+1 dividing σ⁺(n)

Determine whether there exist infinitely many positive composite integers n such that n+1 divides σ⁺(n), where σ⁺(n)=∏_{p\mid n}(σ(p^{v_p(n)})+1).

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Background

Following negative results for specific factorizations and extensive computation with no examples found up to 105, the authors ask about the infinitude of composite integers n satisfying the divisibility n+1 | σ⁺(n). This extends Open question 2 from existence to infinitude.

References

Open question 3: Are there infinitely many positive composite integers $n$ such that $n+1\mid \sigma+(n)$?

Divisibility and Sequence Properties of $σ^+$ and $\varphi^+$ (2508.11660 - Mandal, 6 Aug 2025) in Section 2, Main Results (Open question 3)