Number of nX3 0..3 arrays x(i,j) with each element horizontally, vertically or antidiagonally 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, no adjacent elements equal, and upper left element zero.
A230826
Number of nX3 0..3 arrays x(i,j) with each element horizontally, vertically or antidiagonally 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, no adjacent elements equal, and upper left element zero.
Terms
- a(0) =0a(1) =2a(2) =8a(3) =10a(4) =38a(5) =130a(6) =456a(7) =1610a(8) =5740a(9) =20556a(10) =73752a(11) =264880a(12) =951934a(13) =3422488a(14) =12308046a(15) =44269818a(16) =159246922a(17) =572876878a(18) =2060948396a(19) =7414494752a(20) =26674762316a(21) =95966982642a(22) =345258365956
External references
- oeis: A230826