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.

A084299 Smallest primes such that the subsequent terms of consecutive prime differences (A001223) modulo 6 (A054763) displays repeatedly n times a {0,2,4} pattern of remainders of differences.

Original entry on oeis.org

83, 2903, 5897, 319499, 346943, 7974179, 15262433, 33954251, 5521833683, 83993232497, 848099080883, 1293322433639
Offset: 1

Views

Author

Labos Elemer, Jun 02 2003

Keywords

Examples

			For n=1: a(1) = 83 is followed by [6,8,4].
For n=2: a(2) = 2903 is followed by [6,2,4,18,2,4].
For n=3: a(3) = 5897 is followed by [6,20,4,12,14,28,6,20,4].
For n=4: a(4) = 319499 is followed by [12,8,22,6,20,10,12,2,10,6,32,34].
For n=5: a(5) = 346943 is followed by [18,2,40,....,30,2,10] differences corresponding to n "wavelet" of [0,2,4] remainders modulo 6.
		

Crossrefs

Programs

  • Mathematica
    (* generates a(5) *) d[x_] := Prime[x+1]-Prime[x]; md[x_] := Mod[Prime[x+1]-Prime[x], 6]; h={k1=0, k2=2, k3=4}; k=0; Do[If[Equal[md[n], k1]&&Equal[md[n+1], k2]&& Equal[md[n+2], k3]&&Equal[md[n+3], k1]&&Equal[md[n+4], k2]&&Equal[md[n+5], k3] &&Equal[md[n+6], k1]&&Equal[md[n+7], k2]&&Equal[md[n+8], k3] &&Equal[md[n+9], k1]&&Equal[md[n+10], k2]&&Equal[md[n+11], k3]&& Equal[md[n+12], k1]&&Equal[md[n+13], k2]&&Equal[md[n+14], k3], k=k+1; Print[{k, n, Prime[n], Table[md[n+j], {j, -1, 15}], Table[d[n+j], {j, -1, 15}]}]], {n, 2, 10000000}]
  • PARI
    lista(pmax) = {my(rec = 0, m = 0, c = 0, prv = 2, p0 = 0, d); forprime(p = 3, pmax, d = (p-prv)%6; if(d == 0 && m == 0, p0 = prv); if(d == c, m++; c = (c+2)%6; if(!(m%3) && m/3 > rec, print1(p0, ", "); rec++; m = 0), if(d == 0, p0 = prv; c = 2; m = 1, c = 0; m = 0)); prv = p);} \\ Amiram Eldar, Nov 04 2024

Extensions

a(9)-a(12) from Amiram Eldar, Nov 04 2024

A084301 a(n) = sigma(n) mod 6.

Original entry on oeis.org

1, 3, 4, 1, 0, 0, 2, 3, 1, 0, 0, 4, 2, 0, 0, 1, 0, 3, 2, 0, 2, 0, 0, 0, 1, 0, 4, 2, 0, 0, 2, 3, 0, 0, 0, 1, 2, 0, 2, 0, 0, 0, 2, 0, 0, 0, 0, 4, 3, 3, 0, 2, 0, 0, 0, 0, 2, 0, 0, 0, 2, 0, 2, 1, 0, 0, 2, 0, 0, 0, 0, 3, 2, 0, 4, 2, 0, 0, 2, 0, 1, 0, 0, 2, 0, 0, 0, 0, 0, 0, 4, 0, 2, 0, 0, 0, 2, 3, 0, 1, 0, 0, 2, 0, 0
Offset: 1

Views

Author

Labos Elemer, Jun 02 2003

Keywords

Crossrefs

Sequences sigma(n) mod k: A053866 (k=2), A074941 (k=3), A105824 (k=4), A105825 (k=5), A084301 (k=6), A105826 (k=7), A105827 (k=8).
Cf. A074627 (locations of 0), A074628 (locations of 2), A067051 (locations of 3), A074630 (locations of 4), A074384 (locations of 5).

Programs

Formula

a(n) = A010875(A000203(n)). - Antti Karttunen, Nov 07 2017

A084300 a(n) = phi(n) mod 6.

Original entry on oeis.org

1, 1, 2, 2, 4, 2, 0, 4, 0, 4, 4, 4, 0, 0, 2, 2, 4, 0, 0, 2, 0, 4, 4, 2, 2, 0, 0, 0, 4, 2, 0, 4, 2, 4, 0, 0, 0, 0, 0, 4, 4, 0, 0, 2, 0, 4, 4, 4, 0, 2, 2, 0, 4, 0, 4, 0, 0, 4, 4, 4, 0, 0, 0, 2, 0, 2, 0, 2, 2, 0, 4, 0, 0, 0, 4, 0, 0, 0, 0, 2, 0, 4, 4, 0, 4, 0, 2, 4, 4, 0, 0, 2, 0, 4, 0, 2, 0, 0, 0, 4, 4, 2, 0, 0, 0
Offset: 1

Views

Author

Labos Elemer, Jun 02 2003

Keywords

Crossrefs

Programs

Formula

a(n) = A000010(n) mod 6.
a(n) = A010875(A000010(n)). - Amiram Eldar, Aug 17 2024

A084302 Remainder of tau(n) modulo 6.

Original entry on oeis.org

1, 2, 2, 3, 2, 4, 2, 4, 3, 4, 2, 0, 2, 4, 4, 5, 2, 0, 2, 0, 4, 4, 2, 2, 3, 4, 4, 0, 2, 2, 2, 0, 4, 4, 4, 3, 2, 4, 4, 2, 2, 2, 2, 0, 0, 4, 2, 4, 3, 0, 4, 0, 2, 2, 4, 2, 4, 4, 2, 0, 2, 4, 0, 1, 4, 2, 2, 0, 4, 2, 2, 0, 2, 4, 0, 0, 4, 2, 2, 4, 5, 4, 2, 0, 4, 4, 4, 2, 2, 0, 4, 0, 4, 4, 4, 0, 2, 0, 0, 3, 2, 2, 2, 2, 2
Offset: 1

Views

Author

Labos Elemer, Jun 02 2003

Keywords

Comments

The sums of the first 10^k terms, for k = 1, 2, ..., are 27, 236, 2275, 22166, 220070, 2195376, 21933228, 219259514, 2192385128, 21923168052, ... . Conjecture: the asymptotic mean of this sequence is 3*zeta(3)/zeta(2) = 3 * A253905 = 2.192288... . The conjecture is true if A211337 and A211338 have an equal asymptotic density (see also A059269). - Amiram Eldar, Jul 11 2024

Crossrefs

Programs

Formula

a(n) = A000005(n) modulo 6.
Showing 1-4 of 4 results.