a(n) is the least k such that n*k-1 has exactly n prime factors, counted with multiplicity.

Terms

a(0) =3a(1) =5a(2) =3a(3) =34a(4) =53a(5) =3646a(6) =103a(7) =1367a(8) =57a(9) =5905a(10) =419a(11) =28483073a(12) =5317a(13) =2087804a(14) =12015a(15) =11658487a(16) =28913a(17) =551011827257a(18) =379419a(19) =987922247a(20) =249661a(21) =3328294201a(22) =1914791a(24) =38755369a(25) =271566862001a(26) =4971027a(28) =351453749a(30) =233798623