A292669 Number of matchings in the n-Sierpinski tetrahedron graph.

10, 945, 132820373046, 49123375811021432878640796802876545882185505

Offset

1,1

Links

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

Eric Weisstein's World of Mathematics, Independent Edge Set

Eric Weisstein's World of Mathematics, Matching

Eric Weisstein's World of Mathematics, Sierpinski Tetrahedron Graph

Prog

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

Crossrefs

Sequence in context: A024137 A015008 A194791 * A159869 A006242 A163566

Adjacent sequences: A292666 A292667 A292668 * A292670 A292671 A292672

Keyword

nonn

Author

Eric W. Weisstein, Sep 20 2017

Extensions

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

Status

approved