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 A138856 #10 Sep 06 2024 08:06:05
%S A138856 1,2,4,5,10,16,28,47,83,147,267,481,882,1621,2997,5578,10428,19560,
%T A138856 36849,69649,131983,250841,477992,912662,1746404,3347928,6429526,
%U A138856 12366247,23820901,45947255,88742186,171594310,332169919,643674781,1248523100,2423948034
%N A138856 Numbers such that all subsets of {prime(a(1)), ..., prime(a(n))} have a different sum.
%C A138856 See A138000, A138857 and A138858.
%F A138856 a(n) = primepi(A138000(n)).
%o A138856 (PARI) {s=1;p=0; for( n=1,20, until( !bitand( s, s>>prime(p++) ),); s+=s<<prime(p); print1( p,","))}
%Y A138856 Cf. A064934, A138000, A138001, A138857, A138858.
%K A138856 nonn
%O A138856 1,2
%A A138856 _M. F. Hasler_, Apr 10 2008
%E A138856 a(22)-a(30) from _Donovan Johnson_, Oct 03 2009
%E A138856 a(31)-a(36) from _Amiram Eldar_, Sep 06 2024