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A124177
Consider the map f that sends m to m + (sum of even digits of m) - (sum of odd digits of m). Sequence gives numbers m such that f^(k)(m) = m for some k.
16
0, 22, 26, 27, 34, 35, 44, 49, 52, 63, 66, 78, 79, 81, 88, 99, 104, 107, 108, 112, 115, 121, 126, 133, 134, 143, 144, 151, 156, 165, 178, 187, 211, 224, 229, 232, 233, 283, 290, 314, 336, 341, 358, 363, 385, 413, 431, 467, 470, 489, 492, 516, 538, 561, 583, 615
OFFSET
1,2
COMMENTS
Terms computed by Theunis de Jong.
Subsequence A036301 lists fixed points of the map f = A304440. - M. F. Hasler, May 18 2018
LINKS
Eric Angelini, Self-loopers.
EXAMPLE
26 and 27 loop on themselves, but 28 doesn't.
26 -> 34 -> 35 -> 27 -> 22 -> 26
27 -> 22 -> 26 -> 34 -> 35 -> 27
28 -> 38 -> 43 -> 44 -> 52 -> 49 -> 44.
PROG
(PARI) is(n, S=List())={until(setsearch(Set(S), n=A304440(n)), listput(S, n)); n==S[1]} \\ M. F. Hasler, May 18 2018
KEYWORD
base,easy,nonn
AUTHOR
Eric Angelini, Dec 04 2006
STATUS
approved