Least integer k in A031443 such that k*n is also in A031443, or -1 if there is no such k.

Terms

a(0) =2a(1) =-1a(2) =49a(3) =-1a(4) =2a(5) =2a(6) =535a(7) =-1a(8) =3843a(9) =899a(10) =49a(11) =197a(12) =12a(13) =52a(14) =9a(15) =-1a(16) =9a(17) =10a(18) =2a(19) =9a(20) =2a(21) =2a(22) =35a(23) =9a(24) =2a(25) =2a(26) =147a(27) =2a(28) =2141a(29) =2095