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 A132915 #6 Aug 10 2018 16:14:08
%S A132915 0,1,1,1,2,3,5,8,13,26,47,86,159,292,537,988,1976,3793,7294,14051,
%T A132915 27114,52252,100711,194128,374205,748410,1469706,2887160,5673609,
%U A132915 11153090,21931975,43115540,84761374,166635588,327597567,644042044,1288084088
%N A132915 a(0)=0; a(1)=1; a(n) = Sum_{k=1..[sqrt(n)]} a(n-k) for n>=2.
%C A132915 Lim n->infinity {a(n+1)/a(n)} = 2. Contrast with Fibonacci sequence. Also a(n+1)/a(n) = 2 iff n+1 is square.
%F A132915 a(n) = sum a(n-k), k= 1 ... [sqrt(n)] for n>=2; a(0)=0; a(1)=1.
%e A132915 a(9) = a(6) + a(7) + a(8) = 5 + 8 + 13 = 26.
%Y A132915 Cf. A132916.
%K A132915 nonn
%O A132915 0,5
%A A132915 _Rick L. Shepherd_, Sep 04 2007