Least k such that A056100(k) = 2*n+1 or -1 if no such k exists.

Terms

a(0) =6a(1) =4a(2) =8a(3) =9a(4) =16a(5) =26a(6) =15a(7) =34a(8) =20a(9) =27a(10) =25a(11) =115a(12) =56a(13) =58a(14) =62a(15) =57a(16) =35a(17) =74a(18) =90a(19) =82a(20) =86a(21) =49a(22) =94a(23) =329a(24) =60a(25) =106a(26) =517582a(27) =78a(28) =91a(29) =122