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 1-5 of 5 results.

A197185 The Riemann primes of the psi type and index 1.

Original entry on oeis.org

2, 59, 73, 97, 109, 113, 199, 283, 463, 467, 661, 1103, 1109, 1123, 1129, 1321, 1327, 1423, 2657, 2803, 2861, 3299, 5381, 5881, 6373, 6379, 9859, 9931, 9949, 10337, 10343, 11777, 19181, 19207, 19373, 24107, 24109, 24113, 24121, 24137, 42751, 42793, 42797
Offset: 1

Views

Author

Michel Planat, Oct 11 2011

Keywords

Comments

The sequence consists of the prime numbers p that are champions (left to right maxima) of the function |psi(p)-p|, where psi(p) is the Chebyshev psi function.

Crossrefs

Programs

  • Mathematica
    ChebyshevPsi[n_] := Range[n] // MangoldtLambda // Total;
    Reap[For[max=0; p=2, p<50000, p = NextPrime[p], f = Abs[ChebyshevPsi[p]-p]; If[f > max, max = f; Print[p]; Sow[p]]]][[2, 1]] (* Jean-François Alcover, Dec 03 2018 *)
  • Perl
    use ntheory ":all"; my($max,$f)=(0); forprimes { $f=abs(chebyshev_psi($)-$); if ($f > $max) { say; $max=$f; } } 10000; # Dana Jacobsen, Dec 29 2015

A197186 The Riemann primes of the psi type and index 2.

Original entry on oeis.org

2, 17, 31, 41, 53, 101, 109, 127, 139, 179, 397, 419, 547, 787, 997, 1031, 1229, 1801, 1811, 2099, 2237, 2417, 2423, 2657, 3163, 3203, 3517, 3581, 3583, 3931, 4241, 5503, 5507, 5557, 6079, 8087, 8719, 10433, 10487, 13399, 13411, 19309, 22303, 22307, 22613
Offset: 1

Views

Author

Michel Planat, Oct 11 2011

Keywords

Comments

The sequence consists of the prime numbers p that are champions (left to right maxima) of the function |psi(p^2)-p^2|, where psi(p) is the Chebyshev psi function.

Crossrefs

Programs

  • Mathematica
    ChebyshevPsi[n_] := Range[n] // MangoldtLambda // Total;
    Reap[For[max=0; p=2, p < 2000, p = NextPrime[p], f = Abs[ChebyshevPsi[p^2] - p^2]; If[f > max, max = f; Print[p]; Sow[p]]]][[2, 1]] (* Jean-François Alcover, Dec 03 2018 *)
  • Perl
    use ntheory ":all"; my($max,$f)=(0); forprimes { $f=abs(chebyshev_psi($**2)-$**2); if ($f > $max) { say; $max=$f; } } 10000; # Dana Jacobsen, Dec 29 2015

Extensions

More terms from Dana Jacobsen, Dec 29 2015

A197188 The Riemann primes of the psi type and index 4.

Original entry on oeis.org

2, 5, 7, 11, 13, 17, 31, 41, 43, 71, 89, 103, 109, 139, 173, 191, 197, 241, 281, 317, 443, 487, 569, 577, 701, 761, 797, 919, 1009
Offset: 1

Views

Author

Michel Planat, Oct 11 2011

Keywords

References

  • The sequence consists of the prime numbers p that are champions (left to right maxima) of the function |psi(p^4)-p^4|, where psi(p) is the Chebyshev psi function.

Crossrefs

Programs

  • Perl
    use ntheory ":all"; my($max,$f)=(0); forprimes { $f=abs(chebyshev_psi($**4)-$**4); if ($f > $max) { say; $max=$f; } } 1000; # Dana Jacobsen, Dec 28 2015

Extensions

More terms from Dana Jacobsen, Dec 28 2015

A197299 The Riemann primes of the theta type and index 3.

Original entry on oeis.org

2, 3, 5, 7, 13, 17, 23, 31, 37, 41, 43, 47, 53, 59, 67, 73, 83, 89, 101, 103, 137, 163, 167, 179, 197, 211, 223, 239, 251, 277, 331, 379, 397, 431, 463, 467, 521, 577, 593, 601, 613, 617, 719, 809, 881, 919, 967, 1091, 1123, 1129, 1237, 1249, 1289
Offset: 1

Views

Author

Michel Planat, Oct 13 2011

Keywords

References

  • The sequence consists of the prime numbers p that are champions (left to right maxima) of the function |theta(p^3)-p^3|, where theta(p) is the Chebyshev theta function.

Crossrefs

Programs

  • Perl
    use ntheory ":all"; my($max,$f)=(0); forprimes { $f=abs(chebyshev_theta($**3)-$**3); if ($f > $max) { say; $max=$f; } } 1000; # Dana Jacobsen, Dec 28 2015

Extensions

More terms from Dana Jacobsen, Dec 28 2015

A196184 Positive integers b for which there is a 9-Pythagorean triple (a,b,c) satisfying a<=b.

Original entry on oeis.org

15, 30, 5, 8, 13, 45, 160, 60, 24, 48, 75, 459, 10, 16, 26, 90, 320, 57, 105, 15, 45, 120, 273, 15, 24, 39, 104, 135, 184, 480, 48, 96, 150, 165, 285, 20, 32, 52, 180, 640, 195, 240, 408, 114, 210, 17, 25, 40, 65, 72, 112, 144, 225, 329, 416, 553, 800, 21
Offset: 1

Views

Author

Clark Kimberling, Sep 29 2011

Keywords

Comments

See A195770 for definitions of k-Pythagorean triple, primitive k-Pythagorean triple, and lists of related sequences.

Crossrefs

Programs

Showing 1-5 of 5 results.