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A139680 Number of n X n symmetric binary matrices with no row sum greater than 4. 2
1, 2, 8, 64, 1024, 28217, 1146419, 62951431, 4451407563, 392447922178, 42102440864054, 5391561047209898, 811314950514676762, 141599096294933832181, 28348376853054890615951, 6448749608634353498219753, 1653216120840296892595307251, 474197636984335589673286631814 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Andrew Howroyd, Table of n, a(n) for n = 0..40

CROSSREFS

Column k=4 of A334548.

Sequence in context: A191572 A191573 A136283 * A153544 A153572 A191574

Adjacent sequences:  A139677 A139678 A139679 * A139681 A139682 A139683

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 13 2008

EXTENSIONS

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

STATUS

approved

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Last modified October 5 11:53 EDT 2022. Contains 357255 sequences. (Running on oeis4.)