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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A197564 Number of n X n X n 0..6 triangular arrays with each element equal to the number its zero neighbors. 1
 1, 3, 4, 18, 51, 266, 1518, 11396, 111218, 1345019, 21178437, 420441727, 10691248879, 346431341394, 14306876354446, 754052504644414 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Also the number of maximal independent vertex sets (and minimal vertex covers) in the (n-1)-triangular grid graph. - Eric W. Weisstein, Jun 14 and Aug 07 2017 LINKS Table of n, a(n) for n=1..16. Eric Weisstein's World of Mathematics, Minimal Vertex Cover Eric Weisstein's World of Mathematics, Maximal Independent Vertex Set Eric Weisstein's World of Mathematics, Triangular Grid Graph EXAMPLE Some solutions for 5 X 5 X 5: ......1..........0..........0..........0..........0..........1..........0 .....1.0........2.2........1.2........2.1........1.2........0.2........2.2 ....1.2.2......0.2.0......1.1.0......0.1.1......1.1.0......1.2.0......1.0.1 ...0.2.0.2....2.2.2.2....0.2.2.2....2.2.1.0....0.1.2.2....1.1.1.2....1.2.2.1 ..1.1.1.2.0..0.2.0.2.0..1.2.0.2.0..1.0.1.1.1..1.1.1.0.1..1.0.1.1.0..0.2.0.2.0 CROSSREFS Sequence in context: A025113 A290956 A089427 * A222691 A254201 A222795 Adjacent sequences: A197561 A197562 A197563 * A197565 A197566 A197567 KEYWORD nonn AUTHOR R. H. Hardin, Oct 16 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 April 24 04:14 EDT 2024. Contains 371918 sequences. (Running on oeis4.)