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 A210762 #23 Apr 12 2014 00:54:52 %S A210762 2,2,4,5,4,5,4,5,4,5,8,9,10,11,12,4,5,8,9,10,11,12,14,15,16,17,18,19, %T A210762 4,5,8,9,10,11,14,15,16,17,18,19,4,5,8,9,10,11,14,15,16,17,18,19,4,5, %U A210762 8,9,10,14,15,16,17,18,19,4,5,8,9,10,14,15,16,17 %N A210762 Triangle read by rows in which row n lists the positive integers smaller than the currently largest number in Recamán's sequence A005132 after the n-th stage, but not yet present in Recamán's sequence. %C A210762 The number of positive integers in row n is A210612(n). %H A210762 <a href="/index/Rea#Recaman">Index entries for sequences related to Recamán's sequence</a> %e A210762 Written as an irregular triangle: %e A210762 2; %e A210762 2, 4, 5; %e A210762 4, 5; %e A210762 4, 5; %e A210762 4, 5, 8, 9, 10, 11, 12; %e A210762 4, 5, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19; %e A210762 4, 5, 8, 9, 10, 11, 14, 15, 16, 17, 18, 19; %e A210762 4, 5, 8, 9, 10, 11, 14, 15, 16, 17, 18, 19; %e A210762 4, 5, 8, 9, 10, 14, 15, 16, 17, 18, 19; %p A210762 A210762 := proc(n) %p A210762 local L,maxa ; %p A210762 rec := [seq(A005132(j),j=0..n)] ; %p A210762 maxa := max(op(rec)) ; %p A210762 L := [] ; %p A210762 for i from 0 to maxa do %p A210762 if not member(i,rec) then %p A210762 L := [op(L),i] ; %p A210762 end if; %p A210762 end do; %p A210762 if nops(L) = 0 then %p A210762 return [0] ; %p A210762 end if; %p A210762 L ; %p A210762 end proc: %p A210762 seq(op(A210762(n)),n=1..11) ; # _R. J. Mathar_, Apr 01 2012 %Y A210762 Cf. A005132, A210606-A210613. %K A210762 nonn,tabf,less %O A210762 2,1 %A A210762 _Omar E. Pol_, Mar 25 2012