A066122 - OEIS

A066122

Numbers that in base 2 need one 'Reverse and Add' step to reach a palindrome.

2, 4, 6, 8, 10, 12, 14, 16, 18, 24, 30, 32, 34, 36, 38, 40, 42, 48, 52, 56, 62, 64, 66, 68, 70, 80, 82, 96, 100, 102, 112, 114, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 160, 162, 168, 170, 176, 178, 192, 196, 198, 200, 204, 208, 212, 224

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

The analog of A065206 in base 2. The number of steps starts at 0, so palindromes (cf. A006995) are excluded.

Numbers k such that A066057(k) = 1. - 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!

PROG

(ARIBAS): function b2revadd_steps(k, stop: integer); var c, n, m, steps, rev: integer; begin n := 0; c := 0; while c < stop do m := n; rev := b2reverse(m); steps := 0; while steps < k and m <> rev do m := m + rev; rev := b2reverse(m); inc(steps); end; if steps = k and m = rev then write(n, " "); inc(c); end; inc(n); end; end; b2revadd_steps(1, 66).

(PARI) isok(n, s=1)={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

CROSSREFS

Cf. A006995, A065206, A066057.

Sequences for 2..12 steps needed are: A066123, A066124, A066125, A066126, A066127, A066128, A066129, A066130, A066131, A066132, A066133.

Sequence in context: A368244 A309239 A152966 * A119766 A030143 A343335

Adjacent sequences: A066119 A066120 A066121 * A066123 A066124 A066125

KEYWORD

base,nonn

AUTHOR

Klaus Brockhaus, Dec 08 2001

EXTENSIONS

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

STATUS

approved