A265514 a(n) = largest base-4 palindrome m <= n such that every base-4 digit of m is <= the corresponding digit of n; m is written in base 4.

0, 1, 2, 3, 0, 11, 11, 11, 0, 11, 22, 22, 0, 11, 22, 33, 0, 101, 101, 101, 0, 111, 111, 111, 0, 121, 121, 121, 0, 131, 131, 131, 0, 101, 202, 202, 0, 111, 212, 212, 0, 121, 222, 222, 0, 131, 232, 232, 0, 101, 202, 303, 0, 111, 212, 313, 0, 121, 222, 323, 0, 131, 232, 333, 0, 1001, 1001, 1001, 0, 1001, 1001, 1001, 0