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 1-4 of 4 results.

A184804 Numbers m such that prime(m) is of the form floor(k*sqrt(5)); complement of A184807.

Original entry on oeis.org

1, 5, 6, 7, 10, 11, 16, 19, 20, 21, 24, 28, 29, 31, 32, 35, 38, 39, 42, 46, 48, 52, 53, 55, 56, 59, 60, 61, 65, 66, 68, 71, 74, 77, 80, 83, 84, 87, 91, 93, 94, 96, 97, 98, 99, 100, 101, 103, 109, 110, 113, 114, 116, 117, 120, 121, 122, 123, 130, 133, 136, 137, 138, 140, 141, 144, 145, 150, 152, 153, 154, 155, 157, 160, 165, 166, 168, 171, 172, 174, 175, 182, 183, 184, 186, 189, 190, 191, 193, 195, 200, 201, 204, 207, 208, 212, 213, 215, 216
Offset: 1

Views

Author

Clark Kimberling, Jan 22 2011

Keywords

Examples

			See A184802.
		

Crossrefs

Programs

A184802 Primes of the form floor(k*sqrt(5)).

Original entry on oeis.org

2, 11, 13, 17, 29, 31, 53, 67, 71, 73, 89, 107, 109, 127, 131, 149, 163, 167, 181, 199, 223, 239, 241, 257, 263, 277, 281, 283, 313, 317, 337, 353, 373, 389, 409, 431, 433, 449, 467, 487, 491, 503, 509, 521, 523, 541, 547, 563, 599, 601, 617, 619, 641, 643
Offset: 1

Views

Author

Clark Kimberling, Jan 22 2011

Keywords

Comments

See A184774.

Examples

			The sequence U(n)=floor(n*sqrt(5)) begins with
2,4,6,8,11,13,15,17,20,22,24,26,29,...,
which includes the primes U(1)=2, U(5)=11,...
		

Crossrefs

Programs

  • Mathematica
    r=5^(1/2); s=r/(r-1);
    a[n_]:=Floor [n*r];  (* A022839 *)
    b[n_]:=Floor [n*s];  (* A108598 *)
    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
    A184802, A184803, A184804, A184805, A184806, A184807. *)
  • PARI
    for(k=1,300,isprime(p=sqrtint(k^2*5))&&print1(p",")) \\ M. F. Hasler, Aug 26 2014

A184806 Numbers k such that floor(k*s) is prime, where s = (5 + sqrt(5))/4.

Original entry on oeis.org

2, 3, 4, 11, 13, 21, 23, 24, 26, 33, 34, 44, 46, 54, 56, 57, 63, 76, 77, 84, 87, 96, 99, 106, 107, 109, 117, 126, 127, 129, 139, 149, 150, 162, 170, 172, 183, 192, 193, 199, 203, 210, 212, 220, 222, 232, 233, 243, 245, 253, 255, 256, 265, 276, 308, 315, 316, 319, 325, 328, 336, 339, 349, 358, 361, 378, 382, 388, 392, 398, 402, 409, 411, 419, 421, 441, 454, 455, 464, 472, 474, 475, 485, 504, 514, 518, 524, 527, 535, 537, 548, 558, 560, 570, 580, 581, 587, 588, 591
Offset: 1

Views

Author

Clark Kimberling, Jan 22 2011

Keywords

Examples

			See A184802.
		

Crossrefs

Programs

  • Mathematica
    (See A184802.)
    With[{s=(5+Sqrt[5])/4},Select[Range[600],PrimeQ[Floor[#*s]]&]] (* Harvey P. Dale, Jul 04 2014 *)

A184805 Primes of the form floor(k*s), where s=(5+sqrt(5))/4.

Original entry on oeis.org

3, 5, 7, 19, 23, 37, 41, 43, 47, 59, 61, 79, 83, 97, 101, 103, 113, 137, 139, 151, 157, 173, 179, 191, 193, 197, 211, 227, 229, 233, 251, 269, 271, 293, 307, 311, 331, 347, 349, 359, 367, 379, 383, 397, 401, 419, 421, 439, 443, 457, 461, 463, 479, 499, 557, 569, 571, 577, 587, 593, 607, 613, 631, 647, 653, 683, 691, 701, 709, 719, 727, 739, 743, 757, 761, 797, 821, 823, 839, 853, 857, 859, 877, 911, 929, 937, 947, 953, 967, 971, 991, 1009, 1013, 1031, 1049, 1051, 1061, 1063, 1069
Offset: 1

Views

Author

Clark Kimberling, Jan 22 2011

Keywords

Examples

			See A184802.
		

Crossrefs

Programs

  • Mathematica
    (See A184802.)
    With[{s=(5+Sqrt[5])/4},Select[Table[Floor[s*n],{n,600}],PrimeQ]] (* Harvey P. Dale, Feb 04 2015 *)
Showing 1-4 of 4 results.