|
|
A075420
|
|
Trajectory of n under the Reverse and Add! operation carried out in base 4 (presumably) does not reach a palindrome.
|
|
9
|
|
|
290, 318, 378, 381, 438, 444, 462, 498, 501, 504, 510, 545, 567, 573, 627, 633, 636, 639, 693, 696, 699, 717, 719, 732, 751, 753, 756, 759, 765, 775, 795, 799, 800, 822, 823, 828, 835, 847, 859, 882, 883, 888, 894, 895, 915, 919, 927, 948, 954, 967, 972
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
MATHEMATICA
|
limit = 10^3; (* Assumes that there is no palindrome if none is found before "limit" iterations *)
Select[Range[1000],
Length@NestWhileList[# + IntegerReverse[#, 4] &, #, # !=
IntegerReverse[#, 4] &, 1, limit] == limit + 1 &] (* Robert Price, Oct 16 2019 *)
|
|
PROG
|
(PARI) {stop=1000; for(n=1, 980, k=n; c=0; while(c<stop, a=k; rev=0; while(a>0, d=divrem(a, 4); a=d[1]; rev=4*rev+d[2]); if(rev==k, c=stop+1, k=k+rev; c++)); if(c==stop, print1(n, ", ")))}
|
|
CROSSREFS
|
|
|
KEYWORD
|
base,nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|