Number of interior balls in a truncated tetrahedral arrangement.

Terms

a(0) =0a(1) =10a(2) =52a(3) =149a(4) =324a(5) =600a(6) =1000a(7) =1547a(8) =2264a(9) =3174a(10) =4300a(11) =5665a(12) =7292a(13) =9204a(14) =11424a(15) =13975a(16) =16880a(17) =20162a(18) =23844a(19) =27949a(20) =32500a(21) =37520a(22) =43032a(23) =49059a(24) =55624a(25) =62750a(26) =70460a(27) =78777a(28) =87724a(29) =97324