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

A300345

Number of nX3 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) =1a(1) =6a(2) =9a(3) =26a(4) =57a(5) =133a(6) =306a(7) =709a(8) =1642a(9) =3805a(10) =8811a(11) =20409a(12) =47276a(13) =109514a(14) =253686a(15) =587661a(16) =1361316a(17) =3153496a(18) =7305099a(19) =16922333a(20) =39200767a(21) =90809027a(22) =210360189a(23) =487301922a(24) =1128840861a(25) =2614973750a(26) =6057619008a(27) =14032549467a(28) =32506574899a(29) =75301884294

External references