a(n) is the total number of vertices of degree 3 in Catalan word grid graphs with n parts.
A390116
a(n) is the total number of vertices of degree 3 in Catalan word grid graphs with n parts.
Terms
- a(0) =4a(1) =27a(2) =135a(3) =606a(4) =2585a(5) =10725a(6) =43771a(7) =176800a(8) =709308a(9) =2832710a(10) =11277222a(11) =44796870a(12) =177673275a(13) =703921785a(14) =2786742675a(15) =11026630560a(16) =43615236720a(17) =172480297050a(18) =682006922610
External references
- oeis: A390116