Number of n X 3 (-1,0,1) arrays of determinants of 2 X 2 subblocks of some (n+1) X 4 binary array with rows and columns of the latter in lexicographically nondecreasing order.

A226867

Number of n X 3 (-1,0,1) arrays of determinants of 2 X 2 subblocks of some (n+1) X 4 binary array with rows and columns of the latter in lexicographically nondecreasing order.

Terms

    a(0) =7a(1) =37a(2) =187a(3) =792a(4) =2866a(5) =9136a(6) =26267a(7) =69311a(8) =170084a(9) =392159a(10) =856558a(11) =1784149a(12) =3563340a(13) =6855064a(14) =12751438a(15) =23010044a(16) =40392728a(17) =69146369a(18) =115673477a(19) =189452998a(20) =304286614a(21) =479963424a(22) =744456493a(23) =1136788693a(24) =1710732884a(25) =2539543163

External references