A292968 Number of matchings in the n-Sierpinski sieve graph.

4, 27, 10054, 499058851840, 60978122299433248924629725740007424, 111234802292550535463100810323266662685051007497410845234355027801887222800563874025554401906714958888960

Offset

1,1

Links

Christian Sievers, Table of n, a(n) for n = 1..8

Eric Weisstein's World of Mathematics, Independent Edge Set

Eric Weisstein's World of Mathematics, Matching

Eric Weisstein's World of Mathematics, Sierpinski Sieve Graph

Prog

(PARI) a(n)={my(s=[1, 0, 1, 0]); for(k=2, n, s=vector(4, i, sum(xy=0, 2, sum(xz=0, 2, sum(yz=0, 2, s[1+(i>1)+(xy%2)+(xz%2)]*s[1+(i>2)+(xy\2)+(yz%2)]*s[1+(i>3)+(xz\2)+(yz\2)]))))); [1, 3, 3, 1]*s~} \\ Christian Sievers, Jul 19 2024

Crossrefs

Sequence in context: A008973 A132646 A254866 * A000869 A132640 A307031

Adjacent sequences: A292965 A292966 A292967 * A292969 A292970 A292971

Keyword

nonn

Author

Eric W. Weisstein, Sep 30 2017

Extensions

a(5) and beyond from Christian Sievers, Jul 19 2024

Status

approved