%I #6 Feb 23 2018 09:49:16
%S 0,6,10,16,20,26,30,31,5,1,15,11,25,21,35,27,9,7,19,17,29,32,4,2,14,
%T 12,24,22,34,28,8,18,38,23,3,13,33,36,40,46,50,56,60,66,70,76,80,81,
%U 45,41,55,51,65,61,75,71,85,77,39,37,49,47,59,57,69,67,79,82,44,42,54,52,64,62,74,72,84,78,48,58,68,88,73,43,53,63,83,86,90,96,100
%N Lexicographic first sequence of nonnegative integers such that a(n) + a(n+1) has a digit 6, and no term occurs twice.
%C A permutation of the nonnegative integers.
%o (PARI) a(n,f=1,d=6,a=0,u=[a])={for(n=1,n,f&&if(f==1,print1(a","),write(f,n-1," "a));for(k=u[1]+1,oo,setsearch(u,k)&&next;setsearch(Set(digits(a+k)),d)&&(a=k)&&break);u=setunion(u,[a]);u[2]==u[1]+1&&u=u[^1]);a}
%Y Cf. A299976 (analog with positive terms), A299957 (analog with digit 1), A299970, A299982..A299988, A299969 (digit 0, 2..8, 9).
%K nonn,base
%O 0,2
%A _M. F. Hasler_ and _Eric Angelini_, Feb 22 2018