A124176 Consider the map f that sends m to m + (sum of odd digits of m) - (sum of even digits of m). Sequence gives numbers m such that f^(k)(m) = m for some k.

0, 11, 13, 17, 18, 25, 28, 54, 55, 64, 65, 112, 121, 134, 137, 143, 148, 155, 156, 165, 166, 173, 178, 184, 187, 198, 200, 209, 211, 216, 231, 233, 234, 237, 244, 245, 270, 275, 280, 285, 314, 336, 341, 358, 363, 385, 396, 402, 407, 410, 413, 429, 431, 432

Offset

1,2

Comments

Terms computed by Barry and Theunis de Jong.

Subsequence A036301 lists fixed points of the map f = A304439. - M. F. Hasler, May 18 2018

Links

Eric Angelini, Dec 04 2006, Table of n, a(n) for n = 1..172

Example

11 and 13 loop on themselves, but 12 doesn't:
11 -> 13 -> 17 -> 25 -> 28 -> 18 -> 11
12 -> 11 -> 13 -> 17 -> 25 -> 28 -> 18 -> 11
13 -> 17 -> 25 -> 28 -> 18 -> 11 -> 13.

Prog

(PARI) is(n, S=List())=until(setsearch(Set(S), n=A304439(n)), listput(S, n)); n==S[1] \\ M. F. Hasler, May 18 2018

Crossrefs

Cf. A124177, A036301, A304439; A071648, A071649, A071650.

Sequence in context: A341162 A205693 A068569 * A210757 A031979 A055239

Adjacent sequences: A124173 A124174 A124175 * A124177 A124178 A124179

Keyword

base,easy,nonn

Author

Eric Angelini, Dec 04 2006

Status

approved