Coordination sequence for (2,6,infinity) tiling of hyperbolic plane.

Terms

a(0) =1a(1) =3a(2) =5a(3) =8a(4) =13a(5) =21a(6) =33a(7) =51a(8) =80a(9) =126a(10) =198a(11) =311a(12) =488a(13) =766a(14) =1203a(15) =1889a(16) =2966a(17) =4657a(18) =7312a(19) =11481a(20) =18027a(21) =28305a(22) =44443a(23) =69782a(24) =109568a(25) =172038a(26) =270125a(27) =424136a(28) =665956a(29) =1045649