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.

A330426 Primes P where the distance to the nearest prime is greater than 2*log(P).

Original entry on oeis.org

211, 2179, 2503, 3967, 4177, 7369, 7393, 11027, 11657, 14107, 16033, 16787, 18013, 18617, 18637, 18839, 19661, 21247, 23719, 24281, 29101, 32749, 33247, 33679, 33997, 37747, 38501, 40063, 40387, 42533, 42611, 44417, 46957, 51109, 51383, 53479, 54217, 55291, 55763
Offset: 1

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Author

Steven M. Altschuld, Dec 14 2019

Keywords

Comments

The author suggests that these numbers be called Double Frogger Primes because two times the distance as the average distance to the nearest neighbor (the log) has to be hopped.

Examples

			P = 211 is a term because 199 + 2*log(211) < 211 < 223 - 2*log(211).
P = 199 is not a term because 197 + 2*log(199) > 199.
		

Crossrefs

Cf. A288908 (with 1*log(P)), A330427 (with 3*log(P)), A330428.

Programs

  • Magma
    f:=func;  [p:p in PrimesUpTo(56000)|f(p)];// Marius A. Burtea, Dec 18 2019
  • Maple
    q:= 3: state:= false: count:= 0: Res:= NULL:
    while count < 100 do
      p:= nextprime(q);
      newstate:= is(p-q > 2*log(q));
      if state and newstate then
        count:= count+1; Res:= Res, q;
      fi;
      q:= p; state:= newstate;
    od:
    Res; # Robert Israel, Dec 18 2019
  • Mathematica
    lst={};Do[a=Prime[n];If[Min[Abs[a-NextPrime[a,{-1,1}]]]>2*Log[a],AppendTo[lst,a]],{n,1,10000}];lst (* Metin Sariyar, Dec 15 2019 *)
    (* Second program: *)
    Select[Prime@ Range[10^4], Min@ Abs[# - NextPrime[#, {-1, 1}]] > 2 Log[#] &] (* Michael De Vlieger, Dec 15 2019 *)

Extensions

More terms from Metin Sariyar, Dec 15 2019