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.

A174916 Lesser of twin primes p1 such that p1 + p2^2 - p1^2 is a prime number.

Original entry on oeis.org

3, 5, 11, 17, 29, 71, 101, 281, 311, 419, 461, 521, 599, 617, 641, 659, 809, 827, 857, 881, 1019, 1061, 1277, 1289, 1319, 1607, 1721, 1949, 2027, 2111, 2141, 2309, 2339, 2381, 2591, 2729, 2801, 3329, 3557, 3581, 3767, 3851, 4049, 4127, 4157, 4217, 4229
Offset: 1

Views

Author

Keywords

Comments

3+(5^2-3^2)=3+16=19,..
Let x be the lesser of twin prime pairs. The sequence contains terms such that 5*x+4 is prime. - Harvey P. Dale, Sep 11 2012

Crossrefs

Programs

  • Mathematica
    lst={}; Do[p1=Prime[n]; p2=p1+2; If[PrimeQ[p2] && PrimeQ[p1+(p2^2-p1^2)], AppendTo[lst, p1]], {n, 1000}]; lst
    With[{ltp=Transpose[Select[Partition[Prime[Range[600]],2,1],#[[2]]- #[[1]]==2&]][[1]]}, Select[ltp,PrimeQ[5#+4]&]] (* Harvey P. Dale, Sep 11 2012 *)