Number of 3Xn arrays containing n copies of 0..3-1 with no element 1 greater than its north, northeast or northwest neighbor modulo 3 and the upper left element equal to 0.
A266887
Number of 3Xn arrays containing n copies of 0..3-1 with no element 1 greater than its north, northeast or northwest neighbor modulo 3 and the upper left element equal to 0.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =7a(6) =41a(7) =209a(8) =999a(9) =4603a(10) =20763a(11) =92601a(12) =410279a(13) =1811327a(14) =7982401a(15) =35151819a(16) =154779159a(17) =681698115a(18) =3003887511a(19) =13244742603a(20) =58438985851a(21) =258033686801
External references
- oeis: A266887