A306189 Number of minimum dominating sets in the n-Sierpinski gasket graph.

3, 6, 2, 392, 1656976026, 122836566640423857273582993856, 50043395758253154294953783566500246788902420299683914045600060272160541415159062540151890

Offset

1,1

Links

Christian Sievers, Table of n, a(n) for n = 1..9

Eric Weisstein's World of Mathematics, Minimum Dominating Set.

Eric Weisstein's World of Mathematics, Sierpinski Gasket Graph.

Prog

(PARI) a(n)={my(s=[[1+O(x), 0, 0, 0], [0, 0, x+O(x^2)], [0, x^2+O(x^3)], [x^3+O(x^4)]]); for(k=2, n, s=vector(4, i, vector(5-i, j, sum(xy=0, 3, sum(xz=0, 3, sum(yz=0, 3, s[1+(i>1)+!xy+!xz][1+(j>3)+(xy%2)+(xz%2)]*s[1+(i>2)+!xy+!yz][1+(j>2)+(xy\2)+(yz%2)]*s[1+(i>3)+!xz+!yz][1+(j>1)+(xz\2)+(yz\2)]/x^(!xy+!xz+!yz))))))); pollead([1, 3, 3, 1]*vectorv(4, i, s[i][5-i]))} \\ Christian Sievers, Jul 21 2024, improved Jul 25 2024

Crossrefs

Cf. A347508, A347515, A376478 (domination number).

Sequence in context: A372921 A367028 A349863 * A216803 A094118 A375691

Adjacent sequences: A306186 A306187 A306188 * A306190 A306191 A306192

Keyword

nonn

Author

Eric W. Weisstein, Jan 28 2019

Extensions

a(5) and beyond from Christian Sievers, Jul 21 2024

Status

approved