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 A288119 #16 Jun 14 2017 07:14:29 %S A288119 1,0,2,3,5,4,8,7,6,10,9,11,12,14,13,17,16,15,19,18,20,21,23,22,26,25, %T A288119 24,28,27,29,30,32,31,35,34,33,37,36,38,39,41,40,44,43,42,46,45,47,48, %U A288119 50,49,53,52,51,55,54,56,57,59,58,62,61,60,64,63,65,66,68 %N A288119 Lexicographically earliest sequence of distinct nonnegative terms such that, for any i and j >= 0, a(i+j) != a(i) + a(j). %C A288119 If we drop the unicity constraint, then we obtain A059841. %C A288119 This sequence is a self-inverse permutation of the natural numbers. %C A288119 a(1+2+2) = a(1) + a(2) + a(2). %H A288119 Rémy Sigrist, <a href="/A288119/a288119.pdf">First 9 terms, proof of the formula</a> %H A288119 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A288119 a(n+9) = a(n) + 9 for any n >= 0. %F A288119 G.f.: (1-x+2*x^2+x^3+2*x^4-x^5+4*x^6-x^7-x^8+3*x^9)/((1-x)*(1-x^9)). - _Robert Israel_, Jun 13 2017 %e A288119 See Links section. %p A288119 A[0]:= 1: A[1]:= 0: S:= {0,1}: %p A288119 for n from 2 to 100 do %p A288119 Forbid:= S union {seq(A[i]+A[n-i],i=1..floor(n/2))}; %p A288119 A[n]:= min( {$1..max(Forbid)+1} minus Forbid); %p A288119 S:= S union {A[n]}; %p A288119 od: %p A288119 [seq(A[i],i=0..100)]; # _Robert Israel_, Jun 13 2017 %Y A288119 Cf. A059841. %K A288119 nonn %O A288119 0,3 %A A288119 _Rémy Sigrist_, Jun 05 2017