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.

A157995 Primes which are the sum of 1 plus two consecutive not-twin primes, p1 and p2, (p2-p1)>2.

Original entry on oeis.org

19, 31, 43, 53, 79, 101, 113, 139, 163, 173, 199, 211, 223, 241, 269, 331, 353, 373, 463, 509, 521, 577, 601, 619, 631, 727, 773, 787, 811, 829, 853, 883, 907, 919, 947, 967, 991, 1013, 1031, 1181, 1193, 1231, 1291, 1301, 1361, 1429, 1447, 1483, 1531, 1543
Offset: 1

Views

Author

Keywords

Examples

			19=7+11+1, 31=13+17+1, 43=19+23+1, 53=23+29+1, 79=37+41+1, 101=47+53+1, ...
		

Crossrefs

Programs

  • Maple
    count:= 0: R:= NULL: p:= 2:
    while count < 100 do
      q:= p; p:= nextprime(p);
      if p-q > 2 and isprime(p+q+1) then
         count:= count+1; R:= R, p+q+1
      fi
    od:
    R; # Robert Israel, May 13 2020
  • Mathematica
    lst={};Do[p0=Prime[n];p1=Prime[n+1];a=p0+p1+1;If[PrimeQ[a]&&(p1-p0)>2,AppendTo[lst,a]],{n,6!}];lst
    Select[Total[#]+1&/@Select[Partition[Prime[Range[200]],2,1],Last[#]-First[#]>2&],PrimeQ]  (* Harvey P. Dale, Mar 13 2011 *)

Extensions

Definition corrected by Harvey P. Dale, Mar 13 2011