Number of n X 3 0..1 arrays with diagonals and antidiagonals unimodal and rows nondecreasing.

A223944

Number of n X 3 0..1 arrays with diagonals and antidiagonals unimodal and rows nondecreasing.

Terms

    a(0) =4a(1) =16a(2) =54a(3) =177a(4) =596a(5) =2024a(6) =6869a(7) =23285a(8) =78942a(9) =267681a(10) =907708a(11) =3078001a(12) =10437337a(13) =35392507a(14) =120014445a(15) =406963770a(16) =1379996360a(17) =4679507294a(18) =15868004855a(19) =53807711762a(20) =182459601684a(21) =618712543947

External references