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.

Showing 1-3 of 3 results.

A184796 Primes of the form floor(k*sqrt(3)).

Original entry on oeis.org

3, 5, 13, 17, 19, 29, 31, 41, 43, 53, 67, 71, 79, 83, 103, 107, 109, 131, 157, 173, 181, 193, 197, 199, 211, 223, 233, 239, 251, 263, 271, 277, 311, 313, 337, 349, 353, 367, 379, 389, 401, 419, 431, 433, 439, 443, 457, 467, 479, 491, 509, 521, 523, 547, 557, 569, 571, 587, 599, 601, 607, 613, 647, 659, 661, 673, 677, 691, 701, 727, 739, 743, 751, 769, 827, 829, 853, 857, 859, 881, 883, 907, 911, 919, 937, 947, 971, 983, 997, 1009, 1013, 1021, 1039
Offset: 1

Views

Author

Clark Kimberling, Jan 22 2011

Keywords

Comments

See A184774.
Equals the prime terms of A022838. - Bill McEachen, Oct 28 2021

Examples

			The sequence A022838(n)=floor(n*sqrt(3)) begins with 1,3,5,6,8,10,12,13,15,17,19,... which includes the primes A022838(2)=3, A022838(3)=5, A022838(8)=13,...
		

Crossrefs

Programs

  • Mathematica
    r=3^(1/2); s=r/(r-1);
    a[n_]:=Floor [n*r];  (* A022838 *)
    b[n_]:=Floor [n*s];  (* A054406 *)
    Table[a[n],{n,1,120}]
    t1={};Do[If[PrimeQ[a[n]], AppendTo[t1,a[n]]],{n,1,600}];t1
    t2={};Do[If[PrimeQ[a[n]], AppendTo[t2,n]],{n,1,600}];t2
    t3={};Do[If[MemberQ[t1,Prime[n]],AppendTo[t3,n]],{n,1,300}];t3
    t4={};Do[If[PrimeQ[b[n]], AppendTo[t4,b[n]]],{n,1,600}];t4
    t5={};Do[If[PrimeQ[b[n]], AppendTo[t5,n]],{n,1,600}];t5
    t6={};Do[If[MemberQ[t4,Prime[n]],AppendTo[t6,n]],{n,1,300}];t6
    (* The lists t1, t2, t3, t4, t5, t6 match the sequences
    A184796, A184797, A184798, A184799, A184800, A184801. *)

A184799 Primes of the form floor(k*s), where s=(3+sqrt(3))/2.

Original entry on oeis.org

2, 7, 11, 23, 37, 47, 59, 61, 73, 89, 97, 101, 113, 127, 137, 139, 149, 151, 163, 167, 179, 191, 227, 229, 241, 257, 269, 281, 283, 293, 307, 317, 331, 347, 359, 373, 383, 397, 409, 421, 449, 461, 463, 487, 499, 503, 541, 563, 577, 593, 617, 619, 631, 641, 643, 653, 683, 709, 719, 733, 757, 761
Offset: 1

Views

Author

Clark Kimberling, Jan 22 2011

Keywords

Examples

			See A184796.
		

Crossrefs

Programs

  • Maple
    filter:= proc(p) local v, k;
      v:= p*(1-1/sqrt(3));
      k:= ceil(v);
      is((v-k+1)^2 > 1/3)
    end proc:
    select(filter, [seq(ithprime(i),i=1..200)]); # Robert Israel, May 04 2020
  • Mathematica
    (See A184796.)

A184801 Numbers m such that prime(m) is of the form floor(ks), where s=(3+sqrt(3))/2; complement of A184778.

Original entry on oeis.org

1, 4, 5, 9, 12, 15, 17, 18, 21, 24, 25, 26, 30, 31, 33, 34, 35, 36, 38, 39, 41, 43, 49, 50, 53, 55, 57, 60, 61, 62, 63, 66, 67, 69, 72, 74, 76, 78, 80, 82, 87, 89, 90, 93, 95, 96, 100, 103, 106, 108, 113, 114, 115, 116, 117, 119, 124, 127, 128, 130, 134, 135, 137, 138, 139, 140, 141, 142, 143, 146, 150, 151, 154, 158, 160, 162, 163, 165, 167, 171, 173, 174, 180, 183, 184, 186, 188, 193, 195, 197, 198, 200, 203, 204, 206, 209, 210, 212, 213, 217, 219, 221
Offset: 1

Views

Author

Clark Kimberling, Jan 22 2011

Keywords

Examples

			See A184796.
		

Crossrefs

Programs

Showing 1-3 of 3 results.