The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A191713 Number of n X n symmetric binary matrices with each 1 adjacent to no more than 2 E, S or NW neighboring 1s 1
 2, 8, 56, 760, 19792, 978304, 92183968, 16556792256, 5666183103872, 3695209097658560, 4592223914052994688, 10875252973619159084864, 49078195656242127591078144, 422056710044472651098920886272 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS R. H. Hardin, Table of n, a(n) for n = 1..20 EXAMPLE Some solutions for n=5 ..1..0..0..0..1....0..0..0..0..1....0..1..0..0..0....0..1..1..0..0 ..0..1..0..1..1....0..1..0..0..0....1..0..1..0..1....1..0..1..0..1 ..0..0..0..1..0....0..0..0..0..1....0..1..1..0..0....1..1..1..1..1 ..0..1..1..1..0....0..0..0..0..0....0..0..0..0..0....0..0..1..0..0 ..1..1..0..0..1....1..0..1..0..1....0..1..0..0..1....0..1..1..0..0 CROSSREFS Sequence in context: A135079 A084872 A254231 * A191508 A113725 A256724 Adjacent sequences:  A191710 A191711 A191712 * A191714 A191715 A191716 KEYWORD nonn AUTHOR R. H. Hardin Jun 12 2011 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 20 03:02 EDT 2021. Contains 343121 sequences. (Running on oeis4.)