Coordination sequence for hexagonal close-packing.

Terms

a(0) =1a(1) =12a(2) =44a(3) =96a(4) =170a(5) =264a(6) =380a(7) =516a(8) =674a(9) =852a(10) =1052a(11) =1272a(12) =1514a(13) =1776a(14) =2060a(15) =2364a(16) =2690a(17) =3036a(18) =3404a(19) =3792a(20) =4202a(21) =4632a(22) =5084a(23) =5556a(24) =6050a(25) =6564a(26) =7100a(27) =7656a(28) =8234a(29) =8832