Numerator of Product_{i=1..n} (p_i + 1)/(p_i - 1) where p_i is the i-th prime.

Terms

a(0) =3a(1) =6a(2) =9a(3) =12a(4) =72a(5) =84a(6) =189a(7) =21a(8) =252a(9) =270a(10) =288a(11) =304a(12) =1596a(13) =152a(14) =3648a(15) =49248a(16) =295488a(17) =1526688a(18) =17302464a(19) =622888704a(20) =640191168a(21) =1707176448a(22) =10243058688a(23) =23046882048a(24) =23527025424a(25) =599939148312a(26) =47054050848