login
A240510
Numbers whose "reverse and add" process becomes palindromic at 8813200023188.
5
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
REFERENCES
David Wells, The Penguin Dictionary of Curious and Interesting Numbers. Penguin Books, NY, 1986, Revised edition 1987. See p. 143.
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
Sequence in context: A256240 A090062 A166370 * A039437 A043260 A044040
KEYWORD
base,nonn,fini
AUTHOR
J. Lowell, Apr 06 2014
EXTENSIONS
More terms from Jon E. Schoenfield, Apr 12 2014
STATUS
approved