A292697 Number of independent vertex sets and vertex covers in the n-Sierpinski tetrahedron graph.

5, 43, 111683, 5594439374027693723, 35319181455117794679495200199452640533956657352898505871606802940473343235

Offset

1,1

Links

Christian Sievers, Table of n, a(n) for n = 1..6

Eric Weisstein's World of Mathematics, Independent Vertex Set

Eric Weisstein's World of Mathematics, Sierpinski Tetrahedron Graph

Eric Weisstein's World of Mathematics, Vertex Cover

Prog

(PARI) a(n)={my(s=[1, 1, 0, 0, 0]); for(k=2, n, s=vector(5, i, sum(wx=0, 1, sum(wy=0, 1, sum(wz=0, 1, sum(xy=0, 1, sum(xz=0, 1, sum(yz=0, 1, s[1+(i>1)+wx+wy+wz]*s[1+(i>2)+wx+xy+xz]*s[1+(i>3)+wy+xy+yz]*s[1+(i>4)+wz+xz+yz])))))))); [1, 4, 6, 4, 1]*s~} \\ Christian Sievers, Jul 20 2024

Crossrefs

Sequence in context: A099794 A142726 A079646 * A247712 A030698 A080284

Adjacent sequences: A292694 A292695 A292696 * A292698 A292699 A292700

Keyword

nonn

Author

Eric W. Weisstein, Sep 21 2017

Extensions

a(4) and beyond from Christian Sievers, Jul 20 2024

Status

approved