The equation of Ramanujan-Nagell and [𝑦²]

Mead, D. G.

doi:10.1090/S0002-9939-1973-0327725-4

The equation of Ramanujan-Nagell and $[y^{2}]$
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by D. G. Mead PDF

Proc. Amer. Math. Soc. 41 (1973), 333-341 Request permission

Abstract:

By arithmetizing Levi’s constructive test for membership in [$[{y^2}]$] we have translated the questions of whether a given power product is in [$[{y^2}]$] to determining whether a certain product of matrices is the zero matrix. This leads to number-theoretic problems, including the diophantine equations of the title ${2^n} - 7 = {x^2}$.

References

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Problem

5

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Elementary problem

79