Palindromic in bases 4 and 10.

Terms

a(0) =0a(1) =1a(2) =2a(3) =3a(4) =5a(5) =55a(6) =373a(7) =393a(8) =666a(9) =787a(10) =939a(11) =7997a(12) =53235a(13) =55255a(14) =55655a(15) =57675a(16) =506605a(17) =1801081a(18) =2215122a(19) =3826283a(20) =3866683a(21) =5051505a(22) =5226225a(23) =5259525a(24) =5297925a(25) =5614165a(26) =5679765a(27) =53822835a(28) =623010326a(29) =954656459