A062129 - OEIS

%I #6 Jul 11 2015 00:10:08

%S 0,11,11,1001,101,1111,1001,10101,1001,11011,1111,11011,1111,11011,

%T 10101,101101,10001,110011,11011,1100011,1100011,111111,-1,111111,

%U 11011,1100011,-1,11111111,-1,111111,101101,1011101,100001,1100011,110011,-1,101101,-1,111111,1100011,101101,-1,111111

%N In base 2: start with n; add to itself with digits reversed; if palindrome, stop; otherwise repeat; a(n) gives palindrome at which it stops, or -1 if no palindrome is ever reached.

%C The analog of A061563 in base 2. Differs from A062128 only for those n, which are palindromes in base 2.

%e 23: 10111 -> 10111 + 11101 = 110100 -> 110100 + 1011 = 111111, so a(23) = 111111.

%o (ARIBAS): stop := 500; for k := 0 to 60 do c := 0; m := k; test := true; while test and c < stop do inc(c); m := m + bit_reverse(m); test := m <> bit_reverse(m); end; if c < stop then bit_write(m); else write(-1); end; write(" "); end;.

%Y Cf. A061563, A062128, A062131, A058042.

%K base,easy,sign

%O 0,2

%A _Klaus Brockhaus_, Jun 06 2001