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A090067
Numbers n such that there are (presumably) six palindromes in the Reverse and Add! trajectory of n.
0
7, 12, 17, 21, 26, 30, 33, 35, 53, 59, 62, 68, 71, 80, 86, 88, 95, 102, 103, 109, 114, 117, 142, 150, 154, 170, 191, 201, 208, 209, 210, 213, 216, 222, 241, 253, 300, 301, 303, 307, 308, 312, 315, 329, 340, 352, 359, 383, 389, 400, 404, 406, 407, 411, 428, 451
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 154 begins 154, 605, 1111, 2222, 4444, 8888, 17776, 85547, 160105, 661166, 1322332, 3654563, 7309126, ...; at 7309126 it joins the (presumably) palindrome-free trajectory of A063048(7) = 10577, hence 525, 1551, 5115, 13431, 26862 and 12455421 are the six palindromes in the trajectory of 154 and 154 is a term.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Klaus Brockhaus, Nov 20 2003
STATUS
approved