The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 60th year, we have over 367,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A192841 Number of n X n symmetric 0..2 arrays with each element equal to at least two horizontal or vertical neighbors, containing at least one 2 and with new values 0..2 introduced in lower triangular row major order 0
 0, 0, 0, 1, 11, 346, 8731, 349401, 20156718, 1851292543, 266585533037, 61535828576431, 22709782832888746, 13463873321548595944, 12814751672955863921345 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,5 LINKS Table of n, a(n) for n=1..15. EXAMPLE Some solutions for 6X6 ..0..0..1..1..2..2....0..0..0..0..2..2....0..0..0..0..0..0....0..0..0..0..0..0 ..0..0..1..1..2..2....0..0..0..0..2..2....0..1..1..1..0..0....0..1..1..1..1..0 ..1..1..0..0..0..0....0..0..0..0..0..0....0..1..1..1..1..1....0..1..2..2..1..0 ..1..1..0..0..0..0....0..0..0..1..1..0....0..1..1..1..1..1....0..1..2..2..1..0 ..2..2..0..0..1..1....2..2..0..1..1..0....0..0..1..1..2..2....0..1..1..1..1..0 ..2..2..0..0..1..1....2..2..0..0..0..0....0..0..1..1..2..2....0..0..0..0..0..0 CROSSREFS Sequence in context: A277348 A033517 A279238 * A158788 A012220 A012138 Adjacent sequences: A192838 A192839 A192840 * A192842 A192843 A192844 KEYWORD nonn AUTHOR R. H. Hardin Jul 11 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 9 04:08 EST 2023. Contains 367681 sequences. (Running on oeis4.)