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 A362265 #34 May 28 2023 08:45:59 %S A362265 1,2,5,6,7,9,12,15,17,18,19,20,21,23,25,27,28,30,35,37,39,40,41,42,43, %T A362265 45,47,49,51,52,54,56,61,63,65,67,68,69,70,71,72,73,75,77,79,81,83,86, %U A362265 88,90,97,99,101,103,105,106,107,108,109,110,111,113,115,117,119,121,123,125,126,128,130 %N A362265 Indices m for which A362363(m) = 0, meaning the large spiral point in A362249 falls on the East base spiral. %C A362265 If m is a term then further terms can be found by writing m = s^2 + r such that s^2 is the square closest to m (and r is positive or negative). Then further terms are k = (t*s)^2 + t*r for odd t (but only sometimes even t). %H A362265 Thomas Scheuerle, <a href="/A362265/a362265.png">Spiral of dots.</a> Each dot corresponds to a spiral from A362249. If this spiral meets with spiral "E", the color is blue. Other colors: "S" = orange, "W" = yellow, "N" = violet. Spirals where n in A362249 is an even square number are located on the x axis extending from the midpoint to the right. The odd square numbers extend to the left. %F A362265 All numbers of the form (2*k+1)^2 will be found inside this sequence but not (2*k)^2. %F A362265 All numbers of the form 4^k+2^k, 4*k^2+k and k > 0, 9*(2*k+1)^2-4*k-2, 9*k^2+3*k and k > 0, 16*(2*k+1)^2+2*k+1 will be found inside this sequence. %e A362265 6 is a term since in A362249, its n=6 large spiral point 6 falls on its East base spiral. %Y A362265 Cf. A362249, A000290, A001844, A002061. %K A362265 nonn %O A362265 1,2 %A A362265 _Tamas Sandor Nagy_ and _Thomas Scheuerle_, Apr 13 2023