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

 Please make a donation to keep the OEIS running. We are now in our 56th year. In the past year we added 10000 new sequences and reached almost 9000 citations (which often say "discovered thanks to the OEIS"). Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A230677 Number of 3Xn 0..2 arrays x(i,j) with each element horizontally, diagonally or antidiagonally next to at least one element with value 2-x(i,j) 1
 0, 81, 1173, 18915, 340563, 6081561, 108108231, 1923264723, 34219066161, 608809697883, 10831633601715, 192711252863829, 3428626492612815, 61000479835023903, 1085291316379044081, 19308983258977687575 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Row 3 of A230675 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = 13*a(n-1) +65*a(n-2) +312*a(n-3) +829*a(n-4) +559*a(n-5) -458*a(n-6) -2767*a(n-7) -2801*a(n-8) -1031*a(n-9) -485*a(n-10) -743*a(n-11) -272*a(n-12) +332*a(n-13) +172*a(n-14) -24*a(n-15) for n>16 EXAMPLE Some solutions for n=3 ..0..2..0....2..2..0....2..0..2....0..2..0....2..0..2....0..2..1....0..0..0 ..0..0..2....0..0..2....0..2..2....0..1..1....2..2..0....2..1..1....2..2..0 ..0..2..2....2..1..1....2..0..2....2..0..2....0..2..0....1..0..2....0..0..0 CROSSREFS Sequence in context: A236781 A237059 A236010 * A231994 A236790 A232876 Adjacent sequences:  A230674 A230675 A230676 * A230678 A230679 A230680 KEYWORD nonn AUTHOR R. H. Hardin, Oct 27 2013 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 December 3 20:56 EST 2020. Contains 338920 sequences. (Running on oeis4.)