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 A330318 #10 May 21 2024 09:41:23
%S A330318 1,5,5,5,13,13,13,13,17,25,25,25,25,25,25,25,33,41,41,41,41,41,41,41,
%T A330318 41,65,65,65,65,65,65,65,65,65,65,65,73,73,73,73,89,89,89,89,89,89,89,
%U A330318 89,89,101,101,101,117,117,117,117,117,117,117,117,117,117
%N A330318 a(n) = Sum_{i=0..n} r(i)*r(i+1)/4, where r(n) = A004018(n) is the number of ways of writing n as a sum of two squares.
%D A330318 H. Iwaniec. Spectral methods of automorphic forms, volume 53 of Graduate Studies in Mathematics. American Mathematical Society, Providence, RI, 2002.
%H A330318 Fernando Chamizo, <a href="https://doi.org/10.2969/jmsj/05110237">Correlated sums of r(n)</a>, J. Math. Soc. Japan, 51(1):237-252, 1999.
%H A330318 Fernando Chamizo, and Roberto J. Miatello, <a href="https://arxiv.org/abs/1812.10725">Sums of squares in real quadratic fields and Hilbert modular groups</a>, arXiv preprint arXiv:1812.10725 [math.NT], 2018.
%Y A330318 Cf. A004018, A330315, A330317.
%Y A330318 Partial sums of A330316.
%K A330318 nonn
%O A330318 0,2
%A A330318 _N. J. A. Sloane_, Dec 11 2019