Squares of primes or products of pairs of consecutive primes.

Terms

a(0) =4a(1) =6a(2) =9a(3) =15a(4) =25a(5) =35a(6) =49a(7) =77a(8) =121a(9) =143a(10) =169a(11) =221a(12) =289a(13) =323a(14) =361a(15) =437a(16) =529a(17) =667a(18) =841a(19) =899a(20) =961a(21) =1147a(22) =1369a(23) =1517a(24) =1681a(25) =1763a(26) =1849a(27) =2021a(28) =2209a(29) =2491