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 A183531 #12 May 02 2017 15:35:27 %S A183531 1,2,3,4,5,6,7,8,36,64,65,66,67,68,69,70,71,92,106,120,141,148,792, %T A183531 793,802,803,816,817,820,828,830,838,844,1591,1592,1606,1607,2356, %U A183531 2357,2358,2359,2360,2384,2395,2402,3149,3150,3169,3919,3920,3921,3922,3923 %N A183531 An Ulam-type sequence: a(n) = n if n<=8; for n>8, a(n) = least number > a(n-1) which is a unique sum of 8 distinct earlier terms. %C A183531 An Ulam-type sequence - see A002858 for further information. %H A183531 Alois P. Heinz, <a href="/A183531/b183531.txt">Table of n, a(n) for n = 1..500</a> %H A183531 <a href="/index/U#Ulam_num">Index entries for Ulam numbers</a> %e A183531 a(9) = 36 = 1 + ... + 8 = 8*9/2, because it is the least number >8 with a unique sum of 8 distinct earlier terms. %e A183531 a(10) = 64 = 1 + ... + 7 + 36 = 8^2, because it is the least number >36 with a unique sum of 8 distinct earlier terms. %p A183531 # see A183534 for programs. %Y A183531 Column k=8 of A183534. %Y A183531 Cf. A002858, A007086, A183527-A183533, A135737. %K A183531 nonn %O A183531 1,2 %A A183531 _Jonathan Vos Post_ and _Alois P. Heinz_, Jan 05 2011