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A241174
Smallest number requiring n steps to reach a palindrome under the "add a digit" process described in A241173.
11
0, 10, 13, 12, 17, 89, 1072, 1066, 1058, 1049, 1045, 1039, 1036, 1028, 1019, 1017, 1009, 1007, 998, 994, 988, 100953, 100944, 100935, 100926, 100917, 100908, 100899, 100890, 100882, 100874, 100866, 100858, 100849, 100841, 100833, 100825, 100817, 100809, 100801, 100792, 100784, 100777
OFFSET
0,2
COMMENTS
Beginning with a(6), the palindromic sinks appear to be, for positive n, (10^n+1)*(10^(n+1)+1):
n=1 a(6)-a(20) 1072 to 988
n=2 a(21)-a(157) 100953 to 99980
n=3 a(158)-a(1461) 10^7+9827 to 10^7-20
n=4 a(1462)-a(14078) 10^9+98720 to 10^9-20
n=5 a(14079)-a(137233) 10^11+988091 to 10^11-20
n=6 a(137234)-a(1346435) 10^13+9885167 to 10^13-20
n=7 a(1346436)-a(13265907) 10^15+98879696 to 10^15-20
etc. - Hans Havermann, Apr 23 2014
REFERENCES
Eric Angelini, Posting to Sequence Fans Mailing List, Apr 20 2014
LINKS
MATHEMATICA
A241173[n_] := Module[{c, nx},
If[n == IntegerReverse[n], Return[0]];
c = 1; nx = n;
While[ ! AnyTrue[nx = Union[Flatten[nx + IntegerDigits[nx]]], # == IntegerReverse[#] &], c++];
Return[c]];
A241174[n_] := Module[{i = 0},
While[A241173[i] != n, i++];
Return[i]];
Table[A241174[i], {i, 0, 5}] (* Robert Price, Mar 17 2019 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, Apr 23 2014
EXTENSIONS
More terms from Hans Havermann, Apr 23 2014
STATUS
approved