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 A080570 #2 Mar 31 2012 13:50:44 %S A080570 1,0,1,2,2,2,3,3,4,4,6,6,8,8,11,12,13,15,14,17,18,19,20,21,23,23,24, %T A080570 26,28,32,31,32,35,36,37,43,43,44,44,45,47,50,51,53,53,56,56,57,57,61, %U A080570 62,62,65,68,73,76,77,78,83,83,84,84,87,88,90,92,94,94,97,98,98,101,101 %N A080570 Number of 1's in partition of n-th Ulam number into sum of two distinct Ulam numbers. %e A080570 For n=7: A002858(7) = 11 = 3+8 = (1+2)+(2+6) = (1+2)+(2+(2+4)) = (1+2)+(2+(2+(1+3))) = (1+2)+(2+(2+(1+(1+2)))). Number of 1's in (1+2)+(2+(2+(1+(1+2)))) is 3, so a(7) = 3. %Y A080570 Cf. A002858. %K A080570 easy,nonn %O A080570 1,4 %A A080570 _Naohiro Nomoto_, Feb 22 2003