A065208 Numbers which need three 'Reverse and Add' steps to reach a palindrome.

59, 68, 86, 95, 155, 156, 157, 158, 164, 165, 168, 178, 180, 184, 185, 186, 194, 199, 249, 254, 255, 256, 257, 263, 264, 267, 277, 283, 284, 285, 293, 298, 299, 348, 349, 354, 355, 356, 362, 366, 376, 382, 384, 389, 392, 397, 398, 399, 439, 447, 448, 449, 452, 453, 455, 461, 462, 465, 475, 481, 482

Offset: 1

Author

Klaus Brockhaus, Oct 21 2001

Keywords

• nonn
• base

Comments

The number of steps starts at 0, so palindromes (cf. A002113) are excluded.

Numbers k such that A033665(k) = 3. - Andrew Howroyd, Dec 06 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. A002113, A015979, A033665, A065206.

Programs

ARIBAS

revadd_steps(3,54). For the definition of function revadd_steps see A065206.

Mathematica

palQ[n_]:=Module[{idn=IntegerDigits[n]},idn==Reverse[idn]]
tst[n_]:=palQ/@NestList[#+FromDigits[Reverse[IntegerDigits[#]]]&,n,3]=={False,False,False,True}
Select[Range[750],tst] (* Harvey P. Dale, Nov 26 2010 *)

PARI

isok(n,s=3)={for(k=0, s, my(r=fromdigits(Vecrev(digits(n)))); if(r==n, return(k==s)); n += r); 0} \\ Andrew Howroyd, Dec 06 2024

Extensions

Offset changed from 0 to by Harry J. Smith, Oct 14 2009

More terms from Harvey P. Dale, Nov 26 2010