Number of n X 1 1..4 arrays with no element with value z exactly a city block distance of z from another element with value z.

A210781

Number of n X 1 1..4 arrays with no element with value z exactly a city block distance of z from another element with value z.

Terms

    a(0) =4a(1) =15a(2) =53a(3) =170a(4) =497a(5) =1407a(6) =3962a(7) =10867a(8) =30956a(9) =87542a(10) =248218a(11) =711766a(12) =2029175a(13) =5781750a(14) =16430665a(15) =46462998a(16) =131837484a(17) =374313604a(18) =1064195679a(19) =3028749764a(20) =8608397556a(21) =24458778262a(22) =69472002871a(23) =197274426596a(24) =560475590510

External references