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.

A385538 First differences of A184859.

Original entry on oeis.org

1, 2, 6, 2, 6, 4, 6, 2, 6, 10, 6, 8, 10, 2, 6, 4, 6, 8, 10, 6, 18, 8, 10, 8, 6, 4, 6, 8, 10, 2, 4, 2, 24, 4, 6, 6, 2, 10, 6, 12, 8, 6, 10, 14, 4, 6, 20, 12, 4, 6, 8, 12, 4, 18, 8, 10, 2, 22, 18, 2, 16, 8, 16, 18, 2, 24, 10, 6, 8, 16, 12, 8, 6, 18, 10, 6, 12, 14
Offset: 1

Views

Author

Guido Heinig, Jul 02 2025

Keywords

Crossrefs

Programs

  • Mathematica
    Differences[Select[Floor[Range[420]*GoldenRatio + 1/2], PrimeQ]] (* Amiram Eldar, Jul 10 2025 *)
  • PARI
    lista(nn) = my(v=select(isprime,vector(nn, k, round(k*quadgen(5))))); vector(#v-1, k, v[k+1]-v[k]) \\ Michel Marcus, Jul 08 2025

Formula

a(n) = A184859(n+1) - A184859(n).

A184861 Numbers m such that prime(m) is of the form floor(nr+h), where r=(1+sqrt(5))/2 and h=1/2; complement of A184864.

Original entry on oeis.org

1, 2, 3, 5, 6, 8, 9, 10, 11, 12, 15, 16, 18, 20, 21, 22, 23, 24, 25, 28, 30, 32, 34, 35, 37, 38, 39, 40, 42, 43, 44, 45, 46, 48, 49, 51, 52, 53, 54, 55, 57, 59, 61, 62, 63, 64, 66, 68, 70, 71, 72, 73, 75, 76, 79, 80, 81, 82, 86, 89, 90, 92, 93, 96, 98, 99, 101, 102, 103, 105, 107, 109, 111, 112, 115, 116, 118, 120, 122, 124, 125, 126, 127, 130, 131, 132, 133, 134, 136, 137, 140, 141, 144, 147, 149, 151, 153, 154, 156, 157, 158, 159, 161, 162, 164
Offset: 1

Views

Author

Clark Kimberling, Jan 23 2011

Keywords

Examples

			See A184859.
		

Crossrefs

Programs

  • Mathematica
    r=(1+5^(1/2))/2; h=1/2; s=r/(r-1);
    a[n_]:=Floor [n*r+h];
    Table[a[n], {n, 1, 120}]  (* A007067 *)
    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
    (* Lists t1, t2, t3 match A184859, A184860, A184861. *)

A184860 Numbers k such that floor(nr+h) is prime, where r=(1+sqrt(5))/2 and h=1/2.

Original entry on oeis.org

1, 2, 3, 7, 8, 12, 14, 18, 19, 23, 29, 33, 38, 44, 45, 49, 51, 55, 60, 66, 70, 81, 86, 92, 97, 101, 103, 107, 112, 118, 119, 122, 123, 138, 140, 144, 148, 149, 155, 159, 166, 171, 175, 181, 190, 192, 196, 208, 216, 218, 222, 227, 234, 237, 248, 253, 259, 260, 274, 285, 286, 296, 301, 311, 322, 323, 338, 344, 348, 353, 363, 370, 375, 379, 390, 396, 400, 407, 416, 422, 427, 433, 438, 453, 457, 459, 464, 468, 475, 478, 500, 501, 511, 527, 531, 542, 546, 548, 563, 568, 574, 579, 585, 589, 600
Offset: 1

Views

Author

Clark Kimberling, Jan 23 2011

Keywords

Examples

			See A184859.
		

Crossrefs

Programs

  • Mathematica
    r=(1+5^(1/2))/2; h=1/2; s=r/(r-1);
    a[n_]:=Floor [n*r+h];
    Table[a[n], {n, 1, 120}]  (* A007067 *)
    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
    (* Lists t1, t2, t3 match A184859, A184860, A184861. *)

A184862 Primes of the form floor(n+nr-r/2), where r=(1+sqrt(5))/2.

Original entry on oeis.org

7, 17, 41, 43, 59, 67, 101, 103, 109, 127, 137, 151, 179, 211, 229, 263, 271, 281, 313, 331, 347, 373, 389, 397, 431, 433, 439, 449, 457, 467, 491, 499, 509, 541, 569, 577, 593, 601, 617, 619, 643, 653, 661, 677, 719, 727, 761, 787, 797, 821, 823, 829, 839, 857, 863, 881, 907, 941, 967, 983, 991, 1009, 1033, 1049, 1051, 1069, 1093, 1109, 1117, 1151, 1153, 1187, 1193, 1213, 1229, 1237, 1279, 1289, 1297, 1321, 1373, 1381, 1399, 1423, 1433, 1439, 1483, 1499, 1543, 1549, 1559, 1567
Offset: 1

Views

Author

Clark Kimberling, Jan 23 2011

Keywords

Comments

See "conjecture generalized" at A184774.

Crossrefs

Programs

  • Mathematica
    r=(1+5^(1/2))/2;
    a[n_]:=Floor [n+n*r-r/2];
    Table[a[n],{n,1,120}]  (* A007064 *)
    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
    *( Lists t1, t2, t3 match A184862, A184863, A184864.)
    With[{gr=GoldenRatio},Select[Table[Floor[n+n*gr-gr/2],{n,2000}],PrimeQ]] (* Harvey P. Dale, Sep 18 2024 *)
Showing 1-4 of 4 results.