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 A222582 #10 Oct 21 2019 02:19:09
%S A222582 12,2,0,0,1152,24,26,22,16,12,0,10,10,0,10,9,0,0,0,0,0,8,0,6,8,7,6094,
%T A222582 8,8,8,456,8,6,249,268,133,6,131,120,6,301,7,96,6,6,112,0,79,74,77,6,
%U A222582 6,86,0,0,67,70,65,68,6,6,84,84,6,58,61,56,6,66,6,58
%N A222582 Smallest numbers k such that A006577(n+k) = A006577(n) + A006577(k), or 0 if no such number exists.
%C A222582 A006577 is the number of halving and tripling steps to reach 1 in '3x+1' problem.
%C A222582 a(n) = 0 for n = 3, 4, 11, 14, 17, 18, 19, 20, 21, 23, 47, 54, 55, 73, ...
%e A222582 a(12)=10 because A006577(12+10) = 15, and A006577(12) + A006577(10) = 9 + 6 = 15.
%p A222582 lst:={ }:C:= proc(n) a := 0 ; x := n ; while x > 1 do if type(x, 'even') then x := x/2:a:=a+1: else x := 3*x+1 ; a := a+1 ; end if; end do; a ; end proc:
%p A222582 for n from 1 to 73 do: ii:=0:for k from 2 to 100000 while(ii=0) do:z:=n+k : if C(z)=C(n)+C(k) then ii:=1: printf ( "%d %d \n",n,k):else fi:od: if ii=0 then printf ( "%d %d \n",n,0):else fi:od:
%Y A222582 Cf. A006577, A221947.
%K A222582 nonn
%O A222582 1,1
%A A222582 _Michel Lagneau_, Feb 25 2013