Obtain m by omitting trailing zeros from n; a(n) = smallest k such that k*m is a palindrome with even digits, or -1 if no such multiple exists.

A061916

Obtain m by omitting trailing zeros from n; a(n) = smallest k such that k*m is a palindrome with even digits, or -1 if no such multiple exists.

Terms

    a(0) =1a(1) =2a(2) =1a(3) =2a(4) =1a(5) =-1a(6) =1a(7) =98a(8) =1a(9) =74a(10) =2a(11) =2a(12) =37a(13) =154a(14) =49a(15) =-1a(16) =29a(17) =38a(18) =37a(19) =34a(20) =1a(21) =286a(22) =1a(23) =36a(24) =37a(25) =-1a(26) =77a(27) =329144a(28) =31a(29) =16

External references