a(n) is the number of divisors of n!*(n! + 1)/2.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =18a(5) =36a(6) =96a(7) =144a(8) =336a(9) =1120a(10) =960a(11) =960a(12) =4320a(13) =5760a(14) =9504a(15) =29568a(16) =161280a(17) =80640a(18) =884736a(19) =110592a(20) =155520a(21) =460800a(22) =729600a(23) =2188800a(24) =929280a(25) =1300992a(26) =2040192a(27) =1298304a(28) =3528000a(29) =14112000