T(n,k)=6X6X6 triangular graph coloring a rectangular array: number of nXk 0..20 arrays where 0..20 label nodes of the fully triangulated graph and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.
A223370
T(n,k)=6X6X6 triangular graph coloring a rectangular array: number of nXk 0..20 arrays where 0..20 label nodes of the fully triangulated graph and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.
Terms
- a(0) =21a(1) =90a(2) =90a(3) =420a(4) =990a(5) =420a(6) =1992a(7) =11610a(8) =11610a(9) =1992a(10) =9552a(11) =139158a(12) =357354a(13) =139158a(14) =9552a(15) =45984a(16) =1686042a(17) =11206806a(18) =11206806a(19) =1686042a(20) =45984a(21) =221760a(22) =20537766a(23) =356391222a(24) =933306108a(25) =356391222a(26) =20537766a(27) =221760a(28) =1070208a(29) =250834914
External references
- oeis: A223370