a(n) = least k such that A287620(k) = n.

Terms

a(0) =1a(1) =2a(2) =3a(3) =18a(4) =5a(5) =6a(6) =7a(7) =450a(8) =24a(9) =10a(10) =11a(11) =150a(12) =13a(13) =14a(14) =15a(15) =22050a(16) =17a(17) =192a(18) =19a(19) =90a(20) =21a(21) =22a(22) =23a(23) =7350a(24) =160a(25) =26a(26) =3000a(27) =126a(28) =29a(29) =30