Even-indexed coefficients related to Kirchhoff index of hexagonal (benzene) chains.

Terms

a(0) =1a(1) =6a(2) =19a(3) =64a(4) =185a(5) =542a(6) =1511a(7) =4144a(8) =11329a(9) =29894a(10) =80731a(11) =207696a(12) =556217a(13) =1405566a(14) =3741263a(15) =9328928a(16) =24716353a(17) =60998086a(18) =161022115a(19) =394136864a(20) =1037382905a(21) =2522256670a(22) =6622609463a(23) =16012527312a(24) =41958312193a(25) =100973218566