A139679 Number of n X n symmetric binary matrices with no row sum greater than 3.

1, 2, 8, 64, 809, 13846, 301262, 8035168, 255780779, 9519891214, 407613033836, 19816627136912, 1082142442901863, 65776576008442274, 4416031241930248774, 325289604104049686096, 26137255635911145802777, 2279186202842678350137218, 214713550195887533572753024

Offset

0,2

Links

Andrew Howroyd, Table of n, a(n) for n = 0..100

Crossrefs

Column k=3 of A334548.

Sequence in context: A224801 A191571 A347012 * A005640 A153540 A153568

Adjacent sequences: A139676 A139677 A139678 * A139680 A139681 A139682

Keyword

nonn

Author

R. H. Hardin, Jun 13 2008

Extensions

Terms a(13) and beyond from Andrew Howroyd, May 08 2020

Status

approved