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 A320728 #40 Mar 14 2020 03:22:57
%S A320728 0,1,9,10,25,34,35,49,74,81,83,84,121,130,155,164,165,169,202,225,251,
%T A320728 276,285,286,289,290,361,371,394,420,441,445,454,455,514,515,529,596,
%U A320728 625,645,650,670,679,680,683,729,802,804,841,875,885,934,959,961,968,969,970,1044,1089
%N A320728 Numbers that are sums of consecutive odd squares (or centered octagonal numbers).
%H A320728 <a href="/index/Su#ssq">Index entries for sequences related to sums of squares</a>
%o A320728 (PARI) ok(n)={my(i=sqrtint(n)); i=i-(i%2==0); while(i>0, my(a=i^2, j=i); while(j>0 && a<=n, if(a==n, return(1)); j-=2; a=a+j^2); i-=2); 0}
%o A320728 concat([0], select(ok, [1..1200])) \\ _Antonio Roldán_, Mar 12 2020
%Y A320728 Cf. A000447, A016754, A034705, A152043, A322610, A322611, A322637, A322638, A322640.
%K A320728 nonn
%O A320728 1,3
%A A320728 _Ilya Gutkovskiy_, Dec 21 2018