a(n) = least k such that the remainder when 20^k is divided by k is n.

Terms

a(0) =19a(1) =3a(2) =17a(3) =6a(4) =15a(5) =7a(6) =13a(7) =9a(8) =11a(9) =18a(10) =7989a(11) =92a(12) =973a(13) =33a(14) =611a(15) =24a(16) =2661a(17) =382a(18) =559a(19) =21a(20) =96641237093a(21) =42a(22) =1887a(23) =94a(24) =155a(25) =27a(26) =60403a(27) =36a(28) =7971a(29) =74