login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A244534 Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 5. 3

%I #11 Aug 28 2021 03:15:54

%S 1,0,0,0,0,5,11,12,13,14,50,136,289,477,703,1255,2611,5489,10902,

%T 19712,35455,66651,130014,254737,488041,920461,1741642,3338360,

%U 6453073,12425997,23780944,45451155,87224392,168253246,324863578,625728091,1202953325,2314485753

%N Number of ordered unlabeled rooted trees with n nodes such that the minimal outdegree of inner nodes equals 5.

%H Alois P. Heinz, <a href="/A244534/b244534.txt">Table of n, a(n) for n = 6..1000</a>

%p b:= proc(n, t, k) option remember; `if`(n=0,

%p `if`(t in [0, k], 1, 0), `if`(t>n, 0, add(b(j-1, k$2)*

%p b(n-j, max(0, t-1), k), j=1..n)))

%p end:

%p a:= n-> b(n-1, 5$2) -b(n-1, 6$2):

%p seq(a(n), n=6..50);

%t b[n_, t_, k_] := b[n, t, k] = If[n == 0,

%t If[MemberQ[{0, k}, t], 1, 0], If[t > n, 0, Sum[b[j-1, k, k]*

%t b[n-j, Max[0, t-1], k], {j, n}]]];

%t a[n_] := b[n-1, 5, 5] - b[n-1, 6, 6];

%t Table[a[n], {n, 6, 50}] (* _Jean-François Alcover_, Aug 28 2021, after Maple code *)

%Y Column k=5 of A244530.

%Y Cf. A244459.

%K nonn

%O 6,6

%A _Joerg Arndt_ and _Alois P. Heinz_, Jun 29 2014

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 15 03:36 EDT 2024. Contains 375172 sequences. (Running on oeis4.)