Number of n X 2 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.
A199641
Number of n X 2 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.
Terms
- a(0) =1a(1) =3a(2) =13a(3) =60a(4) =288a(5) =1384a(6) =6628a(7) =31772a(8) =152304a(9) =730036a(10) =3499340a(11) =16773680a(12) =80402532a(13) =385399644a(14) =1847365808a(15) =8855120468a(16) =42445929772a(17) =203459338800a(18) =975257291396
External references
- oeis: A199641