a(n) is the smallest value of k such that number of non-unitary prime divisors of k-th Catalan number, A000108(k) = C(2*k,k)/(k+1) equals n.

A081395

a(n) is the smallest value of k such that number of non-unitary prime divisors of k-th Catalan number, A000108(k) = C(2*k,k)/(k+1) equals n.

Terms

    a(0) =1a(1) =6a(2) =13a(3) =25a(4) =72a(5) =96a(6) =182a(7) =320a(8) =481a(9) =923a(10) =1018a(11) =1321a(12) =1323a(13) =1670a(14) =3457a(15) =3455a(16) =3472a(17) =3464a(18) =3462a(19) =3469a(20) =8222a(21) =9991a(22) =12163a(23) =15838a(24) =17665a(25) =18313a(26) =18480a(27) =19458a(28) =19464a(29) =29708

External references