cp's OEIS Frontend

A333774 a(0) = 0; for n > 0, a(n) = the smallest positive integer not yet appearing in the sequence such that a(n-1) + a(n) contains as a substring either a(n-1) or a(n).

%I A333774 #16 Apr 19 2020 05:21:50
%S A333774 0,1,9,10,2,18,100,3,20,4,30,5,40,6,50,7,60,8,70,200,11,99,300,12,108,
%T A333774 972,107,963,106,954,105,945,104,936,103,927,102,918,101,909,1000,13,
%U A333774 117,1053,116,1044,115,1035,114,1026,113,1017,112,1008,111,999,110,990,109,981,2000,14
%N A333774 a(0) = 0; for n > 0, a(n) = the smallest positive integer not yet appearing in the sequence such that a(n-1) + a(n) contains as a substring either a(n-1) or a(n).
%H A333774 Rémy Sigrist, <a href="/A333774/b333774.txt">Table of n, a(n) for n = 0..10000</a>
%H A333774 Rémy Sigrist, <a href="/A333774/a333774_1.gp.txt">PARI program for A333774</a>
%e A333774 a(1) = 1 as a(0) = a(1) = 0 + 1 = 1 which contains '1' as a substring.
%e A333774 a(2) = 9 as a(1) + a(2) = 1 + 9 = 10 which contains '1' as a substring.
%e A333774 a(4) = 2 as a(3) + a(4) = 10 + 2 = 12 which contains '2' as a substring
%e A333774 a(49) = 1026 as a(48) + a(49) = 114 + 1026 = 1140 which contains '114' as a substring.
%o A333774 (PARI) See Links section.
%Y A333774 Cf. A333775, A333811, A332795, A332703.
%K A333774 nonn,base
%O A333774 0,3
%A A333774 _Scott R. Shannon_, Apr 05 2020