A240510 Numbers whose "reverse and add" process becomes palindromic at 8813200023188.

89, 98, 187, 286, 385, 583, 682, 781, 869, 880, 968, 1297, 1387, 1477, 1567, 1657, 1747, 1837, 1927, 2296, 2386, 2476, 2566, 2656, 2746, 2836, 2926, 3295, 3385, 3475, 3565, 3655, 3745, 3835, 3925, 4294, 4384, 4474, 4564, 4654, 4744, 4834, 4924, 5293, 5383

Offset

1,1

Comments

The "reverse and add" sequence for 178 includes 8813200023188, but it becomes palindromic at 15851, so 178 is not in this sequence.

See interesting patterns of the first differences in A328492. - Robert Price, Oct 16 2019

Links

Daniel Starodubtsev, Table of n, a(n) for n = 1..100000 (terms 1..177 from Robert Price)

Felix Fröhlich, C++ program for this sequence

Mathematica

limit = 10^3; (* Assumes that there is no palindrome if none is found before "limit" iterations *)
Select[Range[0, 50000], (np = #; i = 0;
   While[ ! PalindromeQ[np] && i < limit,
    np = np + IntegerReverse[np]; i++];
np == 8813200023188) &] (* Robert Price, Oct 16 2019 *)

Prog

(PARI) is(n)=my(k=8813200023188); while(n<=k && (d=digits(n))!=(r=Vecrev(d)), n+=fromdigits(r)); n==k; \\ Charles R Greathouse IV, Apr 09 2020

Crossrefs

Cf. A033670, A328492.

Sequence in context: A256240 A090062 A166370 * A039437 A043260 A044040

Adjacent sequences: A240507 A240508 A240509 * A240511 A240512 A240513

Keyword

base,nonn,fini

Author

J. Lowell, Apr 06 2014

Extensions

More terms from Jon E. Schoenfield, Apr 12 2014

Status

approved