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.

A360847 Number of dominating induced trees in the n X n grid graph.

Original entry on oeis.org

1, 8, 65, 1280, 78981, 14605388, 7904828158, 12456744197696, 57118103869618858, 760896261783236975004, 29416443122724544970455433, 3297715940113139272931793598648, 1071333966021766251746119497973623975, 1008129126269380724757869194465038817386728
Offset: 1

Views

Author

Andrew Howroyd, Feb 23 2023

Keywords

Comments

A dominating induced tree in a graph is an acyclic connected induced subgraph whose vertices are a dominating set.

Crossrefs

Main diagonal of A360846.
Cf. A287690 (connected dominating sets), A360203 (induced trees).

A360848 Number of dominating induced trees in the n-ladder graph P_2_X P_n.

Original entry on oeis.org

3, 8, 17, 32, 66, 130, 262, 522, 1046, 2090, 4182, 8362, 16726, 33450, 66902, 133802, 267606, 535210, 1070422, 2140842, 4281686, 8563370, 17126742, 34253482, 68506966, 137013930, 274027862, 548055722, 1096111446, 2192222890, 4384445782, 8768891562
Offset: 1

Views

Author

Andrew Howroyd, Feb 23 2023

Keywords

Crossrefs

Row 2 of A360846.

Programs

  • Mathematica
    LinearRecurrence[{1, 2}, {3, 8, 17, 32}, 50] (* Paolo Xausa, Oct 03 2024 *)
  • PARI
    Vec((3 + 5*x + 3*x^2 - x^3)/((1 + x)*(1 - 2*x)) + O(x^20))

Formula

a(n) = a(n-1) + 2*a(n-2) for n > 4.
G.f.: x*(3 + 5*x + 3*x^2 - x^3)/((1 + x)*(1 - 2*x)).
Showing 1-2 of 2 results.