Number of nX3 0..1 arrays with every element unequal to 1, 2, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

A318209

Number of nX3 0..1 arrays with every element unequal to 1, 2, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

Terms

    a(0) =1a(1) =6a(2) =4a(3) =21a(4) =47a(5) =125a(6) =329a(7) =842a(8) =2254a(9) =5893a(10) =15435a(11) =40669a(12) =106859a(13) =280658a(14) =738110a(15) =1940361a(16) =5099669a(17) =13407853a(18) =35248057a(19) =92658886a(20) =243597948a(21) =640404049a(22) =1683558645a(23) =4425986909a(24) =11635671179a(25) =30589415206a(26) =80417882852a(27) =211414206553

External references