Position of first occurrence of n in A331410.

Terms

a(0) =1a(1) =3a(2) =5a(3) =15a(4) =25a(5) =73a(6) =125a(7) =365a(8) =625a(9) =1249a(10) =3125a(11) =6245a(12) =15625a(13) =31225a(14) =62497a(15) =156125a(16) =312485a(17) =780625a(18) =1560001a(19) =3903125a(20) =7800005a(21) =19515625a(22) =39000025a(23) =78000049a(24) =195000125a(25) =390000245a(26) =1948441249a(27) =3905875009a(28) =7811750017a(29) =19529375045