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 A196380 #5 Mar 30 2012 18:57:49 %S A196380 4,20,15,21,24,48,40,88,35,65,140,84,204,55,133,112,280,56,368,99,225, %T A196380 180,468,220,580,77,119,143,341,80,704,312,840,91,481,364,117,207,255, %U A196380 645,480,544,323,833,140,132,156,684,319,760,176,153,171,483 %N A196380 Positive integers b for which there is a primitive (-4)-Pythagorean triple (a,b,c) satisfying a<=b. %C A196380 See A195770 for definitions of k-Pythagorean triple, primitive k-Pythagorean triple, and lists of related sequences. %t A196380 (See A196376.) %Y A196380 Cf. A195770, A196376, A196379, A196381, A196377. %K A196380 nonn %O A196380 1,1 %A A196380 _Clark Kimberling_, Oct 01 2011