Highly composite numbers that are not a product of two highly composite numbers greater than 1.

Terms

a(0) =1a(1) =2a(2) =6a(3) =60a(4) =180a(5) =840a(6) =1260a(7) =25200a(8) =27720a(9) =83160a(10) =277200a(11) =720720a(12) =1081080a(13) =3603600a(14) =10810800a(15) =32432400a(16) =36756720a(17) =61261200a(18) =110270160a(19) =183783600a(20) =551350800a(21) =698377680a(22) =2095133040a(23) =2327925600a(24) =3491888400a(25) =10475665200a(26) =48886437600a(27) =64250746560a(28) =73329656400a(29) =80313433200