a(n) = binomial(2*c-1, c-1) (mod c^3), where c is the n-th composite.

Terms

a(0) =35a(1) =30a(2) =291a(3) =253a(4) =378a(5) =782a(6) =2404a(7) =1260a(8) =291a(9) =3378a(10) =410a(11) =7899a(12) =3996a(13) =6030a(14) =126a(15) =10988a(16) =11188a(17) =5180a(18) =19712a(19) =8483a(20) =5334a(21) =34394a(22) =1841a(23) =21410a(24) =20580a(25) =39556a(26) =38810a(27) =64260a(28) =35972a(29) =66060