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.

A161847 Denominator of the ratio (prime((n+1)^2) - prime(n^2))/prime(n).

Original entry on oeis.org

2, 3, 1, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277
Offset: 1

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Author

Daniel Tisdale, Jun 20 2009

Keywords

Comments

Conjecture: the sequence (prime((n+1)^2) - prime(n^2))/prime(n) converges to 4.

Examples

			The first few fractions are 5/2, 16/3, 6/1, 44/7, 54/11, ... = A161846/A161847.
		

Crossrefs

Cf. A000040, A011757, A161846 (numerators).

Programs

  • PARI
    a(n) = denominator((prime((n+1)^2) - prime(n^2))/prime(n)); \\ Michel Marcus, May 14 2020

Formula

a(n) = denominator((A011757(n+1) - A011757(n))/A000040(n)). - Petros Hadjicostas, May 13 2020

Extensions

Keyword:frac added by R. J. Mathar, Jun 30 2009
Extended by Ray Chandler, May 06 2010
Various sections edited by Petros Hadjicostas, May 13 2020