cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A327447 a(n) = 4*p(n-1)*p(n+1) - p(n)^2, where p(k) = k-th prime.

Original entry on oeis.org

31, 59, 171, 243, 579, 699, 1203, 1675, 2011, 3331, 3715, 4683, 5859, 6907, 8283, 9451, 12091, 12835, 14523, 17107, 17995, 21235, 24283, 26547, 29763, 32619, 33459, 36483, 42603, 43083, 52435, 54067, 62331, 61755, 70771, 73803, 78307, 84907, 89643, 93211, 103995, 103251, 113259, 114819, 126667, 132987, 141859
Offset: 2

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Author

N. J. A. Sloane, Sep 14 2019

Keywords

Comments

It follows from Sándor et al., Sect. VII.18(b) that a(n) > 0 for all n.

References

  • József Sándor, Dragoslav S. Mitrinovic, and Borislav Crstici, Handbook of Number Theory I, Springer Science & Business Media, 2005, Chapter VII, p. 247, section VII.18(b).

Crossrefs

Programs

  • Mathematica
    With[{p = Prime[Range[50]]}, 4 * p[[1;;-3]] * p[[3;;-1]] - p[[2;;-2]]^2] (* Amiram Eldar, Apr 25 2024 *)
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