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

A301959

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

Terms

    a(0) =3a(1) =6a(2) =16a(3) =40a(4) =100a(5) =252a(6) =632a(7) =1588a(8) =3988a(9) =10016a(10) =25156a(11) =63180a(12) =158680a(13) =398532a(14) =1000932a(15) =2513888a(16) =6313748a(17) =15857276a(18) =39826296a(19) =100025620a(20) =251219060a(21) =630948512a(22) =1584656932a(23) =3979940588a(24) =9995808408a(25) =25104944036a(26) =63052250436a(27) =158358699360

External references