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 A122804 #7 Oct 11 2019 13:55:12
%S A122804 1,4,3,12,10,12,21,32,9,40,55,48,26,28,45,112,17,108,114,180,63,132,
%T A122804 23,168,150,104,270,28,145,150,186,128,99,170,70,252,370,266,39,400,
%U A122804 328,252,301,352,495,92,188,576,245,150,408,468,106,486,165,784,342,406,649
%N A122804 Smallest positive number divisible by n which is not of the form a(i)+a(j) for i and j <= n-1.
%C A122804 Same as A122544, except that a(n) is allowed to take values already in the sequence.
%H A122804 Alois P. Heinz, <a href="/A122804/b122804.txt">Table of n, a(n) for n = 1..1000</a>
%t A122804 f[s_] := Block[{n, k},k = n = Length[s] + 1;While[MemberQ[Union[Plus @@@ Tuples[s, 2]], k], k += n];Append[s, k]];Nest[f, {1}, 60]
%Y A122804 Cf. A122537, A122544, A122805 (a(n)/n), A122806 (complement).
%K A122804 nonn
%O A122804 1,2
%A A122804 _Ray Chandler_, Sep 23 2006