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.

A141633 Primes of the form j-(p(j+3)-p(j))/(p(j+2)-p(j+1)), where p(j)=j-th prime.

Original entry on oeis.org

2, 3, 7, 13, 17, 19, 23, 29, 31, 41, 43, 59, 61, 67, 73, 83, 101, 103, 107, 109, 113, 127, 163, 167, 179, 193, 199, 223, 233, 239, 241, 257, 281, 307, 311, 353, 373, 401, 409, 419, 443, 449, 461, 463, 487, 491, 499, 523, 541, 547, 569, 599, 607, 613, 659, 661, 677, 701, 709
Offset: 1

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Author

Juri-Stepan Gerasimov, Sep 10 2008

Keywords

Comments

Primes of the form j-A031165(j)/A001223(j+1). In cases like j=28 and j=32 which create the same prime (here: 23), the prime is only listed once.

Examples

			If j=12, then 12-(p(12+3)-p(12))/(p(12+2)-p(12+1))=12-(47-37)/(43-41)=7=a(3).
If j=48, then 48-(p(48+3)-p(48))/(p(48+2)-p(48+1))=48-(233-223)/(229-227)=43: prime, in the sequence.
If j=88, then 88-(p(88+3)-p(88))/(p(88+2)-p(88+1))=88-(467-457)/(463-461)=83: prime, in the sequence
		

Crossrefs

Cf. A000040.

Programs

  • Mathematica
    Select[Table[n-(Prime[n+3]-Prime[n])/(Prime[n+2]-Prime[n+1]),{n,1000}],PrimeQ[ #] &&#>0&]//Union (* Harvey P. Dale, Aug 12 2020 *)

Extensions

Corrected definition and examples, added many more terms - R. J. Mathar, Sep 13 2008