n - reversal of base 20 digits of n (written in base 10).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =0a(8) =0a(9) =0a(10) =0a(11) =0a(12) =0a(13) =0a(14) =0a(15) =0a(16) =0a(17) =0a(18) =0a(19) =0a(20) =19a(21) =0a(22) =-19a(23) =-38a(24) =-57a(25) =-76a(26) =-95a(27) =-114a(28) =-133a(29) =-152