Consider the figure made up of a row of n adjacent congruent rectangles, with diagonals of all possible rectangles drawn; a(n) = number of interior vertices where exactly three lines cross.
A336489
Consider the figure made up of a row of n adjacent congruent rectangles, with diagonals of all possible rectangles drawn; a(n) = number of interior vertices where exactly three lines cross.
Terms
- a(0) =0a(1) =1a(2) =2a(3) =8a(4) =18a(5) =32a(6) =50a(7) =102a(8) =126a(9) =198a(10) =286a(11) =390a(12) =510a(13) =742a(14) =878a(15) =1130a(16) =1414a(17) =1770a(18) =2166a(19) =2778a(20) =3186a(21) =3858a(22) =4594a(23) =5342a(24) =6146a(25) =7342a(26) =8294a(27) =9662a(28) =11134a(29) =12710
External references
- oeis: A336489