cp's OEIS Frontend

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.

%I A124177 #26 Jun 18 2021 23:02:16
%S A124177 0,22,26,27,34,35,44,49,52,63,66,78,79,81,88,99,104,107,108,112,115,
%T A124177 121,126,133,134,143,144,151,156,165,178,187,211,224,229,232,233,283,
%U A124177 290,314,336,341,358,363,385,413,431,467,470,489,492,516,538,561,583,615
%N 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.
%C A124177 Terms computed by Theunis de Jong.
%C A124177 Subsequence A036301 lists fixed points of the map f = A304440. - _M. F. Hasler_, May 18 2018
%H A124177 Eric Angelini, <a href="/A124177/b124177.txt">Table of n, a(n) for n = 1..182</a>
%H A124177 Eric Angelini, <a href="http://www.cetteadressecomportecinquantesignes.com/22.htm">Self-loopers</a>.
%e A124177 26 and 27 loop on themselves, but 28 doesn't.
%e A124177 26 -> 34 -> 35 -> 27 -> 22 -> 26
%e A124177 27 -> 22 -> 26 -> 34 -> 35 -> 27
%e A124177 28 -> 38 -> 43 -> 44 -> 52 -> 49 -> 44.
%o A124177 (PARI) is(n,S=List())={until(setsearch(Set(S),n=A304440(n)),listput(S,n));n==S[1]} \\ _M. F. Hasler_, May 18 2018
%Y A124177 Cf. A124176, A036301, A304439, A304440, A071650, A071648, A071649.
%K A124177 base,easy,nonn
%O A124177 1,2
%A A124177 _Eric Angelini_, Dec 04 2006