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 A039596 #39 Oct 17 2024 12:51:08 %S A039596 0,1,55,91,208335 %N A039596 Numbers that are simultaneously triangular and square pyramidal. %C A039596 Equivalent to 0^2 + 1^2 + 2^2 + 3^2 + ... + r^2 = 0 + 1 + 2 + 3 + ... + s = n for some r and s. %D A039596 Joe Roberts, Lure of the Integers, page 245 (entry for 645). %D A039596 David Wells, The Penguin Dictionary of Curious and Interesting Numbers, Penguin Books, p. 108. %H A039596 R. Finkelstein and H. London, <a href="http://dx.doi.org/10.1016/0022-314X(72)90036-4">On triangular numbers which are sums of consecutive squares</a>, J. Number Theory 4 (1972), 455-462. %H A039596 M. Gardner, <a href="/A001110/a001110.jpg">Letter to N. J. A. Sloane, circa Aug 11 1980</a>, concerning A001110, A027568, A039596, etc. %H A039596 H. E. Thomas Jr., <a href="http://www.jstor.org/stable/2315561">Problem 5634</a>, Amer. Math. Monthly, 75 (1968), p. 1018. %e A039596 1^2 + 2^2 + 3^2 + 4^2 + 5^2 = 1 + 2 + 3 + ... + 10 = 55, so 55 is in the sequence. %p A039596 q:= n-> issqr(8*n+1): %p A039596 select(q, [sum(j^2, j=1..n)$n=0..100])[]; # _Alois P. Heinz_, Oct 17 2024 %Y A039596 Intersection of A000217 and A000330. %Y A039596 Cf. A053611, A053612. %K A039596 fini,nonn,full %O A039596 1,3 %A A039596 _Felice Russo_ %E A039596 Additional comments from _Jud McCranie_, Mar 19 2000 %E A039596 Zero inserted by _Daniel Mondot_, Sep 07 2023