A233143 Number of nX4 0..5 arrays with no element x(i,j) adjacent to value 5-x(i,j) horizontally, antidiagonally or vertically, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order.
23, 3727, 845917, 198313130, 46648134615, 10976545771938, 2582927810338210, 607799571521107132, 143023917159921251486, 33655571006177475521033, 7919636704985653736563452, 1863603667625659594920136702
Offset: 1
Keywords
Examples
Some solutions for n=2 ..0..1..2..1....0..1..0..4....0..0..1..0....0..1..1..2....0..1..0..1 ..3..5..2..2....1..1..0..2....2..1..0..0....3..5..1..1....1..1..2..5
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 310*a(n-1) -19831*a(n-2) +567817*a(n-3) -9045239*a(n-4) +90083339*a(n-5) -602192427*a(n-6) +2821467285*a(n-7) -9491948537*a(n-8) +23238614757*a(n-9) -41808469376*a(n-10) +55264690349*a(n-11) -51692358938*a(n-12) +30252784146*a(n-13) -5648166713*a(n-14) -6372298968*a(n-15) +4876472605*a(n-16) -104115359*a(n-17) -1424089179*a(n-18) +752282173*a(n-19) -147512539*a(n-20) -22839*a(n-21) +3406138*a(n-22) -81513*a(n-23) -44431*a(n-24) -3578*a(n-25) +468*a(n-26) +81*a(n-27) for n>28
Comments