(n-1)! divided by (product phi(d)! ; d divides n).

Terms

a(0) =1a(1) =1a(2) =1a(3) =3a(4) =1a(5) =30a(6) =1a(7) =105a(8) =28a(9) =630a(10) =1a(11) =207900a(12) =1a(13) =12012a(14) =45045a(15) =675675a(16) =1a(17) =171531360a(18) =1a(19) =2618916300a(20) =3527160a(21) =3879876a(22) =1a(24) =10626a(25) =67603900a(26) =43743700a(28) =1a(30) =1a(32) =14902327440