Number of nX1 1..4 arrays with every element value z a city block distance of exactly z from another element value z.

A209390

Number of nX1 1..4 arrays with every element value z a city block distance of exactly z from another element value z.

Terms

    a(0) =0a(1) =1a(2) =1a(3) =3a(4) =3a(5) =13a(6) =16a(7) =42a(8) =74a(9) =161a(10) =303a(11) =631a(12) =1212a(13) =2446a(14) =4847a(15) =9714a(16) =19142a(17) =38031a(18) =75367a(19) =149813a(20) =296961a(21) =589537a(22) =1169118a(23) =2319453a(24) =4603741a(25) =9137804a(26) =18132445a(27) =35982420a(28) =71413411a(29) =141734249

External references