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 1-2 of 2 results.

A108531 Number of mobiles (cycle rooted trees) with n nodes and 2-colored internal (non-leaf) nodes.

Original entry on oeis.org

1, 2, 6, 18, 60, 206, 770, 2950, 11748, 47746, 197808, 830878, 3532790, 15168294, 65683552, 286504378, 1257693038, 5551978426, 24630911086, 109759215338, 491060888588, 2204938828766, 9933016712348, 44881199711338
Offset: 1

Views

Author

Christian G. Bower, Jun 07 2005

Keywords

Crossrefs

Programs

  • PARI
    CIK(p,n)={sum(d=1, n, eulerphi(d)/d*log(subst(1/(1+O(x*x^(n\d))-p), x, x^d)))}
    seq(n)={my(p=O(1));for(i=1, n, p=1+2*CIK(x*p, i)); Vec(p)} \\ Andrew Howroyd, Jun 20 2018

Formula

Shifts left and halves under CIK transform.

A108532 Number of asymmetric mobiles (cycle rooted trees) with n nodes and 2-colored internal (non-leaf) nodes.

Original entry on oeis.org

1, 2, 4, 12, 38, 136, 490, 1852, 7108, 27880, 110892, 447060, 1821252, 7489732, 31045350, 129587996, 544228664, 2298008824, 9750218012, 41548438040, 177740526076, 763046178960, 3286318131646, 14195239150556, 61481540391722
Offset: 1

Views

Author

Christian G. Bower, Jun 07 2005

Keywords

Crossrefs

Programs

  • PARI
    CHK(p,n)={sum(d=1, n, moebius(d)/d*log(subst(1/(1+O(x*x^(n\d))-p), x, x^d)))}
    seq(n)={my(p=O(1));for(i=1, n, p=1+2*CHK(x*p, i)); Vec(p)} \\ Andrew Howroyd, Jun 20 2018

Formula

Shifts left and halves under CHK transform.
Showing 1-2 of 2 results.