Ramanujan's highly composite numbers A002182 sandwiched between nonprimes.

Terms

a(0) =120a(1) =1680a(2) =25200a(3) =27720a(4) =50400a(5) =83160a(6) =221760a(7) =277200a(8) =554400a(9) =720720a(10) =2162160a(11) =2882880a(12) =3603600a(13) =7207200a(14) =8648640a(15) =10810800a(16) =17297280a(17) =21621600a(18) =36756720a(19) =73513440a(20) =122522400a(21) =147026880a(22) =245044800a(23) =294053760a(24) =551350800a(25) =2095133040a(26) =2327925600a(27) =2793510720a(28) =3491888400