Number of nX4 0..1 arrays with every element equal to 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

A300346

Number of nX4 0..1 arrays with every element equal to 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

Terms

    a(0) =2a(1) =15a(2) =26a(3) =58a(4) =152a(5) =325a(6) =729a(7) =1609a(8) =3577a(9) =7931a(10) =17605a(11) =39106a(12) =86859a(13) =192976a(14) =428779a(15) =952794a(16) =2117289a(17) =4705103a(18) =10455942a(19) =23235911a(20) =51636607a(21) =114750985a(22) =255009010a(23) =566702101a(24) =1259372546a(25) =2798682776a(26) =6219466851a(27) =13821419716a(28) =30715116147

External references