Squarefree numbers of the form (prime(k)+1)*(prime(k+1)+1)/4.

Terms

a(0) =3a(1) =6a(2) =42a(3) =399a(4) =462a(5) =930a(6) =1054a(7) =3135a(8) =4830a(9) =6478a(10) =13110a(11) =19599a(12) =20022a(13) =24963a(14) =26394a(15) =35530a(16) =38805a(17) =39999a(18) =41205a(19) =44310a(20) =52899a(21) =71002a(22) =74254a(23) =81510a(24) =94863a(25) =95790a(26) =103362a(27) =109230a(28) =111547a(29) =114243