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.

A039705 a(n) = n-th prime modulo 7.

Original entry on oeis.org

2, 3, 5, 0, 4, 6, 3, 5, 2, 1, 3, 2, 6, 1, 5, 4, 3, 5, 4, 1, 3, 2, 6, 5, 6, 3, 5, 2, 4, 1, 1, 5, 4, 6, 2, 4, 3, 2, 6, 5, 4, 6, 2, 4, 1, 3, 1, 6, 3, 5, 2, 1, 3, 6, 5, 4, 3, 5, 4, 1, 3, 6, 6, 3, 5, 2, 2, 1, 4, 6, 3, 2, 3, 2, 1, 5, 4, 5, 2, 3, 6, 1, 4, 6, 5, 2, 1, 2, 6, 1, 5, 3, 4, 1, 2, 6, 5, 3, 5, 2, 1, 4, 3, 2, 4
Offset: 1

Views

Author

Keywords

Comments

a(A049084(A045370(n-1))) is even; a(A049084(A045415(n-1))) is odd. - Reinhard Zumkeller, Feb 25 2008

Crossrefs

Programs

Formula

Sum_k={1..n} a(k) ~ (7/2)*n. - Amiram Eldar, Dec 11 2024

A045356 Primes congruent to {0, 2, 4} mod 5.

Original entry on oeis.org

2, 5, 7, 17, 19, 29, 37, 47, 59, 67, 79, 89, 97, 107, 109, 127, 137, 139, 149, 157, 167, 179, 197, 199, 227, 229, 239, 257, 269, 277, 307, 317, 337, 347, 349, 359, 367, 379, 389, 397, 409, 419, 439, 449, 457, 467
Offset: 1

Views

Author

Keywords

Comments

A039703(A049084(a(n))) = even; complement of A045429. - Reinhard Zumkeller, Feb 25 2008

Crossrefs

Programs

  • Magma
    [ p: p in PrimesUpTo(1000) | p mod 5 in {0, 2, 4} ]; // Vincenzo Librandi, Aug 07 2012
  • Mathematica
    Select[Prime[Range[400]], MemberQ[{0, 2, 4}, Mod[#, 5]] &] (* Vincenzo Librandi, Aug 07 2012 *)
    Select[Prime[Range[100]], EvenQ[Mod[#, 5]] &]  (* Zak Seidov, Aug 31 2012 *)
    Select[Flatten[#+{0,2,4}&/@(5*Range[0,100])],PrimeQ] (* Harvey P. Dale, Sep 14 2019 *)

A045415 Primes congruent to {1, 3, 5} mod 7.

Original entry on oeis.org

3, 5, 17, 19, 29, 31, 43, 47, 59, 61, 71, 73, 89, 101, 103, 113, 127, 131, 157, 173, 197, 199, 211, 227, 229, 239, 241, 257, 269, 271, 281, 283, 311, 313, 337, 353, 367, 379, 383, 397, 409, 421, 439, 449, 463, 467
Offset: 1

Views

Author

Keywords

Comments

A039705(A049084(a(n))) = odd; complement of A045370. - Reinhard Zumkeller, Feb 25 2008

Crossrefs

Programs

  • Magma
    [ p: p in PrimesUpTo(600) | p mod 7 in {1,3,5} ]; // Vincenzo Librandi, Aug 12 2012
  • Mathematica
    Select[Prime[Range[100]],MemberQ[{1,3,5},Mod[#,7]]&] (* Harvey P. Dale, May 15 2011 *)

A137977 Primes congruent to {0, 2, 4, 6, 8, 10} modulo 11.

Original entry on oeis.org

2, 11, 13, 17, 19, 37, 41, 43, 59, 61, 79, 83, 101, 103, 107, 109, 127, 131, 149, 151, 167, 173, 191, 193, 197, 211, 233, 239, 241, 257, 263, 277, 281, 283, 307, 347, 349, 367, 373, 389, 409, 431, 433, 439, 457, 461, 479, 499, 503, 521, 523, 541, 547, 563, 569
Offset: 1

Views

Author

Reinhard Zumkeller, Feb 25 2008

Keywords

Comments

A039709(A049084(a(n))) = even; complement of A137978.

Crossrefs

Programs

  • Magma
    [p: p in PrimesUpTo(600) | p mod 11 in [0..10 by 2]]; // Vincenzo Librandi, Aug 15 2012
  • Mathematica
    Select[Prime[Range[200]], MemberQ[{0, 2, 4, 6, 8, 10}, Mod[#, 11]] &] (* Vincenzo Librandi, Aug 15 2012 *)
    Select[Prime[Range[110]], EvenQ[Mod[#, 11]] &] (* Bruno Berselli, Aug 31 2012 *)
Showing 1-4 of 4 results.