Coordination sequence for tridymite, lonsdaleite, and wurtzite.

Terms

a(0) =1a(1) =4a(2) =12a(3) =25a(4) =44a(5) =67a(6) =96a(7) =130a(8) =170a(9) =214a(10) =264a(11) =319a(12) =380a(13) =445a(14) =516a(15) =592a(16) =674a(17) =760a(18) =852a(19) =949a(20) =1052a(21) =1159a(22) =1272a(23) =1390a(24) =1514a(25) =1642a(26) =1776a(27) =1915a(28) =2060a(29) =2209