cp's OEIS Frontend

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.

%I A124176 #23 Jan 25 2024 07:53:49
%S A124176 0,11,13,17,18,25,28,54,55,64,65,112,121,134,137,143,148,155,156,165,
%T A124176 166,173,178,184,187,198,200,209,211,216,231,233,234,237,244,245,270,
%U A124176 275,280,285,314,336,341,358,363,385,396,402,407,410,413,429,431,432
%N 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.
%C A124176 Terms computed by Barry and Theunis de Jong.
%C A124176 Subsequence A036301 lists fixed points of the map f = A304439. - _M. F. Hasler_, May 18 2018
%H A124176 Eric Angelini, Dec 04 2006, <a href="/A124176/b124176.txt">Table of n, a(n) for n = 1..172</a>
%e A124176 11 and 13 loop on themselves, but 12 doesn't:
%e A124176 11 -> 13 -> 17 -> 25 -> 28 -> 18 -> 11
%e A124176 12 -> 11 -> 13 -> 17 -> 25 -> 28 -> 18 -> 11
%e A124176 13 -> 17 -> 25 -> 28 -> 18 -> 11 -> 13.
%o A124176 (PARI) is(n,S=List())=until(setsearch(Set(S),n=A304439(n)),listput(S,n));n==S[1] \\ _M. F. Hasler_, May 18 2018
%Y A124176 Cf. A124177, A036301, A304439; A071648, A071649, A071650.
%K A124176 base,easy,nonn
%O A124176 1,2
%A A124176 _Eric Angelini_, Dec 04 2006