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A217252
Lucky numbers whose digital reversal is another lucky number.
1
13, 15, 31, 37, 51, 73, 115, 133, 163, 169, 189, 193, 195, 327, 331, 339, 361, 385, 391, 399, 511, 529, 537, 579, 583, 591, 723, 729, 735, 739, 925, 927, 933, 937, 961, 975, 981, 993
OFFSET
1,1
COMMENTS
Inspired by the error in A140291 (forgotten palindromes 33 and 99), pointed out by L. Edson Jeffery in a post to the SeqFan list.
This sequence is obtained from A118561 by removal of the palindromes A031161 = (1, 3, 7, 9, 33, 99, 111, 141, 151, 171, 303, 393, 535, 717, 727, 777, 787, 979, ...)
By analogy with the "emirps" A006567 and "emirpimes" A097393, these might be called "ykcul"s, for lucky numbers which, when reversed, are different lucky numbers.
LINKS
FORMULA
A217252 = A118561 \ A031161 = A118561 \ A002113 = A118561 intersect A029742 = { n in A000959 | R(n) is in A000959 and different from n }, where R = A004086.
KEYWORD
base,nonn
AUTHOR
M. F. Hasler, Mar 16 2013
STATUS
approved