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 1-3 of 3 results.

A307549 Number of longest paths in the n-Apollonian network.

Original entry on oeis.org

12, 174, 3084, 35971776, 2752830231727104, 9068533325994694179911466663936, 55357290942669201825421134704769198540735968154850291354435584
Offset: 1

Views

Author

Eric W. Weisstein, Apr 14 2019

Keywords

Crossrefs

Cf. A292002, A307457 (longest path lengths).

Extensions

a(5) onwards from Andrew Howroyd, Jun 09 2025

A302718 Number of cycles in the n-Apollonian network.

Original entry on oeis.org

7, 119, 27850, 2635637428, 40538274896917926642, 18915440603912727411772352213199539580794, 4811072124719412065599148626063536230790419188877913496386013668865001860521888965
Offset: 1

Views

Author

Eric W. Weisstein, Apr 14 2018

Keywords

Comments

a(8) has 165 decimal digits and a(9) has 331 decimal digits. - Andrew Howroyd, Sep 09 2019

Crossrefs

Programs

  • PARI
    P(c,d)={[2*d^3 + 7*d^2 + (6*c + 2)*d + 2*c, 3*d^2 + 5*d + (c + 1)]}
    R(c,d)={16*d^3 + (9*c + 51)*d^2 + (30*c + 27)*d + (3*c^2 + 9*c + 4)}
    a(n)={my(s=1, c=0, d=0); for(i=1, n, s = 3*s + R(c,d); [c,d]=P(c,d)); s} \\ Andrew Howroyd, Sep 10 2019

Extensions

a(5)-a(7) from Andrew Howroyd, Sep 09 2019

A301650 Number of longest cycles in the n-Apollonian network.

Original entry on oeis.org

3, 12, 162, 354294, 1694577218886, 38766491335360039793593446, 20288351481136358057581328834353447021191164711091366
Offset: 1

Views

Author

Eric W. Weisstein, Mar 25 2018

Keywords

Comments

From Andrew Howroyd, Sep 09 2019: (Start)
a(8) has 106 decimal digits and a(9) has 213 decimal digits.
The circumference or length of the longest cycle is given by 7*2^(n-2) for n > 1. For n = 1, the circumference is 4. (End)

Crossrefs

Programs

  • PARI
    P(c,d,x)={[d^2 + 6*c*d + 2*d^3 + 2*x*(c + 3*d^2) + 2*x^2*d, c + d + 3*d^2 + 4*x*d + x^2]}
    R(c,d,x)={4*d^3 + 9*c*d^2 + 3*d^2 + 6*c*d + 3*c^2 + 6*x*(2*d^3 + 3*d^2 + 4*c*d) + 3*x^2*(10*d^2 + 3*d + 3*c) + x^3*(18*d + 1) + 3*x^4}
    a(n)={my(s=x^3, c=0, d=0); for(i=1, n, s = 3*s + R(c,d,x); [c,d]=P(c,d,x)); pollead(s)} \\ Andrew Howroyd, Sep 10 2019

Extensions

a(5)-a(7) from Andrew Howroyd, Sep 09 2019
Showing 1-3 of 3 results.