A066123 Numbers that in base 2 need two 'Reverse and Add' steps to reach a palindrome.

11, 13, 23, 29, 39, 43, 53, 55, 57, 59, 69, 79, 81, 87, 91, 109, 117, 121, 133, 143, 151, 161, 167, 171, 173, 175, 179, 181, 183, 205, 207, 213, 215, 229, 233, 235, 237, 239, 241, 243, 245, 247, 261, 265, 277, 287, 289, 303, 311, 321, 327, 337, 343, 347, 349

Offset: 1

Author

Klaus Brockhaus, Dec 08 2001

Keywords

• base
• nonn

Comments

The analog of A065207 in base 2. The number of steps starts at 0, so palindromes (cf. A006995) are excluded.

Numbers k such that A066057(k) = 2. - Andrew Howroyd, Dec 05 2024

Links

• Harry J. Smith, Table of n, a(n) for n = 1..1000
• Index entries for sequences related to Reverse and Add!

Crossrefs

Cf. A006995, A065207, A066057, A066122.

Programs

PARI

isok(n,s=2)={for(k=0, s, my(r=fromdigits(Vecrev(binary(n)),2)); if(r==n, return(k==s)); n += r); 0} \\ Andrew Howroyd, Dec 05 2024

Extensions

Offset changed from 0 to 1 by Harry J. Smith, Feb 01 2010