Number of n X 3 0..1 arrays with each 1 horizontally or vertically adjacent to 1 or 4 1s.

A295115

Number of n X 3 0..1 arrays with each 1 horizontally or vertically adjacent to 1 or 4 1s.

Terms

    a(0) =3a(1) =9a(2) =26a(3) =77a(4) =226a(5) =665a(6) =1960a(7) =5769a(8) =16983a(9) =49998a(10) =147198a(11) =433361a(12) =1275825a(13) =3756068a(14) =11058011a(15) =32555211a(16) =95843749a(17) =282167522a(18) =830711657a(19) =2445646047a(20) =7200072866a(21) =21197281911a(22) =62405585330a(23) =183724361820a(24) =540891347189

External references