1/12 the number of (n+2)X4 0..2 arrays with each 3X3 subblock containing one of one value, three of another, and five of the last.

A184500

1/12 the number of (n+2)X4 0..2 arrays with each 3X3 subblock containing one of one value, three of another, and five of the last.

Terms

    a(0) =1248a(1) =4546a(2) =17077a(3) =66822a(4) =281876a(5) =1216766a(6) =5366312a(7) =24695528a(8) =114505124a(9) =534949496a(10) =2567370992a(11) =12316518616a(12) =59141443312a(13) =289367917056

External references