Number of nX2 1..2 arrays with every element value z a city block distance of exactly z from another element value z.

A209604

Number of nX2 1..2 arrays with every element value z a city block distance of exactly z from another element value z.

Terms

    a(0) =1a(1) =2a(2) =11a(3) =45a(4) =170a(5) =538a(6) =1674a(7) =5410a(8) =18001a(9) =60486a(10) =202486a(11) =674159a(12) =2238695a(13) =7433743a(14) =24704751a(15) =82150290a(16) =273210105a(17) =908536081a(18) =3020918528a(19) =10044214676a(20) =33396046046a(21) =111040661940a(22) =369210326847

External references