Number of n X 3 array permutations with each element not moving, or moving one space E, S or NW.

A189604

Number of n X 3 array permutations with each element not moving, or moving one space E, S or NW.

Terms

    a(0) =1a(1) =6a(2) =20a(3) =72a(4) =256a(5) =912a(6) =3248a(7) =11568a(8) =41200a(9) =146736a(10) =522608a(11) =1861296a(12) =6629104a(13) =23609904a(14) =84087920a(15) =299483568a(16) =1066626544a(17) =3798846768a(18) =13529793392a(19) =48187073712a(20) =171620807920a(21) =611236571184

External references