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A090065
Numbers n such that there are (presumably) four palindromes in the Reverse and Add! trajectory of n.
0
9, 19, 28, 29, 37, 38, 39, 46, 47, 48, 56, 57, 64, 65, 73, 74, 75, 82, 83, 84, 91, 92, 93, 110, 112, 121, 124, 132, 134, 135, 136, 138, 144, 147, 155, 164, 166, 174, 182, 186, 190, 192, 211, 212, 219, 223, 229, 230, 231, 233, 234, 235, 237, 240, 243, 246, 249
OFFSET
1,1
COMMENTS
For terms < 2000 each palindrome is reached from the preceding one or from the start in at most 24 steps; after the presumably last one no further palindrome is reached in 2000 steps.
EXAMPLE
The trajectory of 134 begins 134, 565, 1130, 1441, 2882, 5764, 10439, 103840, 152141, 293392, 586784, 1074469, ...; at 1074469 it joins the (presumably) palindrome-free trajectory of A063048(72) = 90379, hence 565, 1441, 2882 and 293392 are the four palindromes in the trajectory of 134 and 134 is a term.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Klaus Brockhaus, Nov 20 2003
STATUS
approved