Coordination sequence for quartz.

Terms

a(0) =1a(1) =4a(2) =12a(3) =30a(4) =52a(5) =80a(6) =116a(7) =156a(8) =204a(9) =258a(10) =318a(11) =384a(12) =458a(13) =536a(14) =622a(15) =714a(16) =812a(17) =916a(18) =1028a(19) =1144a(20) =1268a(21) =1398a(22) =1534a(23) =1676a(24) =1826a(25) =1980a(26) =2142a(27) =2310a(28) =2484a(29) =2664