Rolling icosahedron face footprints: number of 2 X n 0..19 arrays starting with 0 where 0..19 label faces of an icosahedron and every array movement to a horizontal, diagonal or antidiagonal neighbor moves across an icosahedral edge.

A223283

Rolling icosahedron face footprints: number of 2 X n 0..19 arrays starting with 0 where 0..19 label faces of an icosahedron and every array movement to a horizontal, diagonal or antidiagonal neighbor moves across an icosahedral edge.

Terms

    a(0) =20a(1) =15a(2) =87a(3) =351a(4) =1575a(5) =6831a(6) =29943a(7) =130815a(8) =572103a(9) =2501199a(10) =10936215a(11) =47815839a(12) =209064807a(13) =914089455a(14) =3996657207a(15) =17474508351a(16) =76403468295a(17) =334057454991

External references