This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A304439 #6 Aug 12 2021 11:04:48
%S A304439 0,2,0,6,0,10,0,14,0,18,11,13,11,17,11,21,11,25,11,29,18,20,18,24,18,
%T A304439 28,18,32,18,36,33,35,33,39,33,43,33,47,33,51,36,38,36,42,36,46,36,50,
%U A304439 36,54,55,57,55,61,55,65,55,69,55,73,54,56,54,60,54,64,54,68,54,72
%N A304439 Add to n the sum of its odd digits minus the sum of its even digits.
%C A304439 Subsequence A036301 lists fixed points of this map, the first nontrivial one being 112. It is a subsequence of A124176 (and A124177) which considers iterations of this map, more precisely, numbers which are in a cyclic orbit for iterations of this map.
%F A304439 a(n) = n + A071650(n).
%t A304439 soded[n_]:=Module[{idn=IntegerDigits[n]},n+Total[Select[idn,OddQ]]-Total[ Select[idn,EvenQ]]]; Array[soded,70,0] (* _Harvey P. Dale_, Aug 12 2021 *)
%o A304439 (PARI) A304439(n)=n-vecsum(apply(t->t*(-1)^t,digits(n)))
%Y A304439 Cf. A304440, A071650, A071648, A071649, A036301, A124176, A124177.
%K A304439 nonn,base
%O A304439 0,2
%A A304439 _M. F. Hasler_, May 18 2018