a(n) is the least k such that the remainder when 10^k is divided by k is n.

Terms

a(0) =3a(1) =14a(2) =7a(3) =6a(4) =35a(5) =94a(6) =993a(7) =46a(8) =22963573117a(9) =11a(11) =22a(12) =21a(13) =86a(14) =99985a(15) =24a(16) =221819a(17) =82a(18) =327a(19) =1996a(20) =28039a(21) =26a(22) =169a(23) =38a(24) =39a(25) =74a(26) =24257a(27) =36a(28) =10191082613a(29) =65a(30) =49