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 A173498 #4 May 27 2021 09:24:02
%S A173498 2,9,61,2194,2592601,3374954133663,5695183504482491594510172,
%T A173498 16217557574922386301420519886707289378131172220652,
%U A173498 131504586847961235687181874578063117114329409897566535831366955410641808739121788386036154689297602
%N A173498 Partial sums of A005588.
%C A173498 Partial sums of number of free binary rooted trees of height n. The subsequence of primes in this partial sum begins: 2, 61, no more through a(12).
%F A173498 a(n) = Sum_{i=1..n} A005588(i).
%e A173498 a(9) = 2 + 7 + 52 + 2133 + 2590407 + 3374951541062 + 5695183504479116640376509 + 16217557574922386301420514191523784895639577710480 + 131504586847961235687181874578063117114329409897550318273792033024340388219235081096658023517076950.
%Y A173498 Cf. A005588, A002658, A006894.
%K A173498 nonn
%O A173498 1,1
%A A173498 _Jonathan Vos Post_, Feb 19 2010