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.

A175873 Primes of the form prime(k+1) + prime(k+2) - prime(k).

Original entry on oeis.org

13, 17, 19, 23, 37, 47, 67, 89, 103, 107, 109, 113, 131, 151, 173, 193, 199, 233, 239, 269, 277, 317, 353, 359, 373, 389, 409, 431, 433, 443, 449, 463, 467, 499, 503, 563, 577, 593, 607, 619, 653, 709, 719, 727, 773, 811, 823, 829, 863, 881, 887, 911, 937, 947, 997, 1033
Offset: 1

Views

Author

Claudio Meller, Dec 05 2010

Keywords

Comments

Some terms can be obtained in more than one way.
For example 47 =37+41-31 = 41+43-37.
The formula in the definition adds a previous prime gap prime(k+1)-prime(k) to the prime(k+2); the gap is basically >=2, so there is a minimal growth which yields safe bounds to algorithms.

Examples

			13 = 7+11-5, 17=11+13-7
		

Programs

  • PARI
    list(lim)=my(v=List(),t,p=2,q=3); forprime(r=5,lim-2, t=q+r-p; if(isprime(t) && t<=lim, listput(v,t)); p=q; q=r); Set(v) \\ Charles R Greathouse IV, Feb 23 2017