a(0) = 0; for n>0, a(n) = maximal number of regions into which space can be divided by n spheres.

Terms

a(0) =0a(1) =2a(2) =4a(3) =8a(4) =16a(5) =30a(6) =52a(7) =84a(8) =128a(9) =186a(10) =260a(11) =352a(12) =464a(13) =598a(14) =756a(15) =940a(16) =1152a(17) =1394a(18) =1668a(19) =1976a(20) =2320a(21) =2702a(22) =3124a(23) =3588a(24) =4096a(25) =4650a(26) =5252a(27) =5904a(28) =6608a(29) =7366