%I A139142
%S A139142 1,3,9,20,37,61,93,135,188,253,331
%N A139142 This sequence and A139143 are complements. a(1)=1. A139143(1)=2. a(n+1) 
               = a(n) + sum{k=1 to n} A139143(k).
%H A139142 Leroy Quet, <a href="http://www.prism-of-spirals.net/">Home Page</a> 
               (listed in lieu of email address)
%e A139142 A139143 consists of all positive integers not in A139142 and vice versa.
%e A139142 A specific example: a(5) = a(4) + sum{k=1 to 4} A139143(k) = 20 + 2+4+5+6 
               = 37.
%Y A139142 Cf. A139143.
%Y A139142 Sequence in context: A033315 A073716 A037048 this_sequence A037257 A145068 
               A027114
%Y A139142 Adjacent sequences: A139139 A139140 A139141 this_sequence A139143 A139144 
               A139145
%K A139142 more,nonn
%O A139142 1,2
%A A139142 Leroy Quet Apr 10 2008