1/4 the number of (n+1) X 2 binary arrays with equal numbers of 2 X 2 subblocks with sums 1 and 3.

A184596

1/4 the number of (n+1) X 2 binary arrays with equal numbers of 2 X 2 subblocks with sums 1 and 3.

Terms

    a(0) =2a(1) =5a(2) =16a(3) =58a(4) =214a(5) =784a(6) =2880a(7) =10704a(8) =40264a(9) =152728a(10) =582424a(11) =2229856a(12) =8566528a(13) =33011680a(14) =127553920a(15) =493989568a(16) =1916920384a(17) =7451582080a(18) =29011376256a(19) =113108257920a(20) =441536615296

External references