%I #13 May 02 2017 15:34:55
%S 1,2,3,4,5,6,7,28,49,50,51,52,53,54,55,70,82,91,109,112,555,556,563,
%T 564,572,573,576,583,584,591,593,1103,1104,1105,1111,1112,1124,1632,
%U 1637,1642,1643,1648,1653,1654,1655,1656,1657,1660,1661,1662,1671,1672,2184
%N An Ulam-type sequence: a(n) = n if n<=7; for n>7, a(n) = least number > a(n-1) which is a unique sum of 7 distinct earlier terms.
%C An Ulam-type sequence - see A002858 for further information.
%H Alois P. Heinz, <a href="/A183530/b183530.txt">Table of n, a(n) for n = 1..500</a>
%H <a href="/index/U#Ulam_num">Index entries for Ulam numbers</a>
%e a(8) = 28 = 1 + ... + 7 = 7*8/2, because it is the least number >7 with a unique sum of 7 distinct earlier terms.
%e a(9) = 49 = 1 + ... + 6 + 28 = 7^2, because it is the least number >28 with a unique sum of 7 distinct earlier terms.
%p # see A183534 for programs.
%Y Column k=7 of A183534.
%Y Cf. A002858, A007086, A183527-A183533, A135737.
%K nonn
%O 1,2
%A _Jonathan Vos Post_ and _Alois P. Heinz_, Jan 05 2011