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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A220546 Number of ways to reciprocally link elements of an n X n array either to themselves or to exactly one horizontal, vertical or antidiagonal neighbor 1
 1, 8, 224, 32173, 21668208, 69961268156, 1077372801893440, 79222784184855853978, 27809964251933826835780981, 46605836505704256743057461864323 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Diagonal of A220553 LINKS R. H. Hardin, Table of n, a(n) for n = 1..12 EXAMPLE Some solutions for n=3 0=self 2=n 3=ne 4=w 6=e 7=sw 8=s (reciprocal directions total 10) ..0..8..8....0..0..8....6..4..7....8..0..0....6..4..0....8..6..4....0..0..7 ..8..2..2....0..7..2....8..3..0....2..8..8....0..7..0....2..8..0....0..3..0 ..2..0..0....3..0..0....2..0..0....0..2..2....3..6..4....0..2..0....0..6..4 CROSSREFS Sequence in context: A230144 A013377 A214383 * A189445 A193786 A213799 Adjacent sequences: A220543 A220544 A220545 * A220547 A220548 A220549 KEYWORD nonn AUTHOR R. H. Hardin Dec 15 2012 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 August 15 11:07 EDT 2024. Contains 375173 sequences. (Running on oeis4.)