Number of n X 2 0..3 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 4 and at least one element with value (x(i,j)-1) mod 4, and upper left element zero.
A230800
Number of n X 2 0..3 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 4 and at least one element with value (x(i,j)-1) mod 4, and upper left element zero.
Terms
- a(0) =0a(1) =2a(2) =2a(3) =16a(4) =34a(5) =154a(6) =432a(7) =1618a(8) =5058a(9) =17664a(10) =57586a(11) =195866a(12) =648928a(13) =2185122a(14) =7284482a(15) =24435056a(16) =81651394a(17) =273490714a(18) =914714512a(19) =3062116338a(20) =10245066178a(21) =34289257824a(22) =114738331026a(23) =383986878106
External references
- oeis: A230800