A139675 Number of n X n symmetric binary matrices with all row sums 8.

1, 2620, 8372754, 30649435140, 133475706272700, 711040444591249476, 4686484162304929219950, 38295413179145036856212700, 386860001875783390762182911250, 4805622573099374975572752075805000, 72929153106385401417284439399165879652

Offset

8,2

Links

Andrew Howroyd, Table of n, a(n) for n = 8..20

Crossrefs

Column k=8 of A333157 and row 8 of A188448.

Sequence in context: A180330 A238921 A156398 * A292175 A295482 A236621

Adjacent sequences: A139672 A139673 A139674 * A139676 A139677 A139678

Keyword

nonn

Author

R. H. Hardin, Jun 12 2008

Extensions

Terms a(13) and beyond from Andrew Howroyd, Mar 09 2020

Status

approved