Denominator of sum of reciprocals of all prime divisors of all positive integers <= n.

Terms

a(0) =1a(1) =2a(2) =6a(3) =3a(4) =15a(5) =30a(6) =210a(7) =105a(8) =35a(9) =70a(10) =770a(11) =1155a(12) =15015a(13) =30030a(14) =30030a(15) =15015a(16) =255255a(17) =170170a(18) =3233230a(19) =1616615a(20) =4849845a(21) =9699690a(22) =223092870a(23) =111546435a(24) =22309287a(25) =44618574a(26) =14872858a(27) =7436429a(28) =215656441a(29) =6469693230