cp's OEIS Frontend

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.

A239786 Number of Pythagorean triangles (x, y, z) with legs x < y < 10^n.

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%I A239786 #18 Feb 16 2025 08:33:21
%S A239786 2,62,1032,14471,185860,2269783,26809918,309224749,3503495999,
%T A239786 39147452720,432599522187
%N A239786 Number of Pythagorean triangles (x, y, z) with legs x < y < 10^n.
%C A239786 A Pythagorean triangle is a right triangle with integer side length x, y, z forming a Pythagorean triple (x, y, z).
%C A239786 Because (x, y, z) is equivalent to (y, x, z), the total number of Pythagorean triangles with legs x, y < 10^n is b(n) = 2*a(n) = 4, 124, 2064, 28942, ...
%H A239786 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PythagoreanTriangle.html">Pythagorean Triangle</a>.
%H A239786 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PythagoreanTriple.html">Pythagorean Triple</a>.
%Y A239786 Cf. A008846, A020882, A020883, A020884, A046086, A046087, A101931, A101929, A239581, A239744.
%K A239786 nonn,more
%O A239786 1,1
%A A239786 _Martin Renner_, Mar 26 2014
%E A239786 a(5)-a(11) from _Giovanni Resta_, Mar 27 2014