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 A206239 #13 Mar 30 2012 16:52:09 %S A206239 0,1,4,24,309,8807,530356,65679652,16512273616,8370804628178, %T A206239 8525389679187197,17408681737224080093,71192609533782031405771, %U A206239 582711051458083440858730497,9542765396943645975520145941300,312620974584432225019935558843189172,20485270547000003746699189223065768145956 %N A206239 Subsequence A005318(t_n), where t_n is the n-th triangular number (A000217). %C A206239 These are the repeated terms in A205744. %H A206239 R. K. Guy, <a href="http://dx.doi.org/10.1016/S0304-0208(08)73500-X">Sets of integers whose subsets have distinct sums</a>, pp. 141-154 of Theory and practice of combinatorics. Ed. A. Rosa, G. Sabidussi and J. Turgeon. Annals of Discrete Mathematics, 12. North-Holland 1982. See Table 1. %Y A206239 Cf. A005318, A205744, A096858. %K A206239 nonn %O A206239 1,3 %A A206239 _N. J. A. Sloane_, Feb 09 2012