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.

User: Michael Burkhart

Michael Burkhart's wiki page.

Michael Burkhart has authored 5 sequences.

A182378 G.f. satisfies A(x) = 1 + x*cycle_index(Sym(7), A(x)).

Original entry on oeis.org

1, 1, 1, 2, 4, 9, 20, 48, 115, 285, 716, 1833, 4740, 12410, 32754, 87176, 233547, 629540, 1705809, 4644231, 12697500, 34848694, 95973026, 265142431, 734606478, 2040683413, 5682634446, 15859800889, 44355531103, 124290064228, 348904212741, 981082979409
Offset: 0

Author

Michael Burkhart, Apr 26 2012

Keywords

Comments

Number of rooted trees where each node has at most 7 children.

Programs

  • Maple
    b:= proc(n, i, t, k) option remember; `if`(n=0, 1,
          `if`(i<1, 0, add(binomial(b((i-1)$2, k$2)+j-1, j)*
           b(n-i*j, i-1, t-j, k), j=0..min(t, n/i))))
        end:
    a:= n-> `if`(n=0, 1, b(n-1$2, 7$2)):
    seq(a(n), n=0..35);  # Alois P. Heinz, Sep 20 2017
  • Mathematica
    b[n_, i_, t_, k_] := b[n, i, t, k] = If[n == 0, 1, If[i < 1, 0, Sum[ Binomial[ b[i-1, i-1, k, k] + j - 1, j]*b[n-i*j, i-1, t-j, k], {j, 0, Min[t, n/i]}]]];
    a[n_] := If[n == 0, 1, b[n-1, n-1, 7, 7]];
    Table[a[n], {n, 0, 35}] (* Jean-François Alcover, Jan 15 2018, after Alois P. Heinz *)

Formula

a(n) = Sum_{j=1..7} A244372(n,j) for n>0, a(0) = 1. - Alois P. Heinz, Sep 19 2017
a(n) / a(n+1) ~ 0.338512011286603947719604869750539045616436718225097926729820... - Robert A. Russell, Feb 11 2023

Extensions

More terms from Patrick Devlin, Apr 29 2012

A182371 Number of connected labeled graphs with n nodes and n+11 edges.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 1330, 6905220, 7279892361, 3717889913655, 1255470137209650, 326123611416074340, 70993993399632155710, 13659118629343706026053, 2405832308811599670396135, 397496768417871214784702640, 62693059156926401902640364120, 9561367292987041683030275944320
Offset: 1

Author

Michael Burkhart, Apr 26 2012

Keywords

Crossrefs

A diagonal of A343088.
Cf. A057500.

Programs

  • Maple
    N:=20: [seq(coeff(op(i, [seq(coeff(taylor(log(add(x^i*(1+y)^(binomial(i, 2))/i!, i=0..N)), x=0, N+1), x, i)*i!, i=1..N)]), y, i-1+12), i=1..N)];

Extensions

Offset corrected and terms a(17) and beyond from Andrew Howroyd, Apr 16 2021

A182295 Number of connected labeled graphs with n nodes and n+10 edges.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 5985, 13112470, 8535294180, 3096620034795, 800118566011380, 166591475854153740, 30012638793107746776, 4892304538906805158775, 743352352817243899253160, 107478174967432322995403280, 15008321493306766503800761840, 2046331888629918743459557040544
Offset: 1

Author

Michael Burkhart, Apr 23 2012

Keywords

Crossrefs

A diagonal of A343088.
Cf. A057500.

Programs

  • Maple
    N:=20: [seq(coeff(op(i,[seq(coeff(taylor(log(add(x^i*(1+y)^(binomial(i,2))/i!,i=0..N)),x=0,N+1),x,i)*i!,i=1..N)]),y,i-1+11),i=1..N)];

Extensions

Offset corrected and terms a(16) and beyond from Andrew Howroyd, Apr 16 2021

A182294 Number of connected labeled graphs with n nodes and n+9 edges.

Original entry on oeis.org

0, 0, 0, 0, 0, 1, 20349, 21426300, 8956859646, 2352103292070, 470090359867986, 79002015147719136, 11836068369346126698, 1640443794179544776604, 215598057543037336382670, 27336005392867324870778880, 3385297472808136707459580488, 413211903044379104303226531072
Offset: 1

Author

Michael Burkhart, Apr 23 2012

Keywords

Crossrefs

A diagonal of A343088.
Cf. A057500.

Programs

  • Maple
    N:=20: [seq(coeff(op(i,[seq(coeff(taylor(log(add(x^i*(1+y)^(binomial(i,2))/i!,i=0..N)),x=0,N+1),x,i)*i!,i=1..N)]),y,i-1+10),i=1..N)];

Extensions

Offset corrected and terms a(16) and beyond from Andrew Howroyd, Apr 16 2021

A207539 Dodecanacci numbers (12th-order Fibonacci sequence): a(n) = a(n-1) +...+ a(n-12) with a(0)=...=a(11)=1.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 12, 23, 45, 89, 177, 353, 705, 1409, 2817, 5633, 11265, 22529, 45057, 90102, 180181, 360317, 720545, 1440913, 2881473, 5762241, 11523073, 23043329, 46081025, 92150785, 184279041, 368513025, 736935948, 1473691715
Offset: 0

Author

Michael Burkhart, Feb 18 2012

Keywords

Crossrefs

Programs

  • Maple
    f12:=proc(n) option remember: if n<=12 then 1: else add(f12(n-i),i=1..12): fi: end:
  • Mathematica
    LinearRecurrence[Table[1, {12}], Table[1, {12}], 100]
  • PARI
    x='x+O('x^50); Vec((1-x-x^2-x^3-x^4-x^5-x^6-x^7-x^8-x^9-x^10-x^11 +10*x^12)/(1-2*x+x^13)) \\ G. C. Greubel, Jul 28 2017

Formula

G.f.: (1-x-x^2-x^3-x^4-x^5-x^6-x^7-x^8-x^9-x^10-x^11 +10*x^12)/(1 -2*x +x^13).