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 A326309 #42 Nov 07 2019 13:42:47
%S A326309 30,84,182,234,240,260,306,312,374,462,476,510,532,546,570,650,828,
%T A326309 840,870,900,920,966,986,1050,1100,1188,1254,1260,1276,1320,1330,1364,
%U A326309 1392,1406,1508,1554,1612,1624,1716,1722,1736,1794,1820,1850,1860,1886,2070,2214,2220
%N A326309 Ordered perimeters p of primitive Pythagorean triangles having short leg in common with the long leg or hypotenuse of a primitive Pythagorean triangle with perimeter < p, and also having both the long leg and the hypotenuse in common with the short legs of primitive Pythagorean triangles with perimeter > p.
%C A326309 The short leg of a primitive Pythagorean triangle of perimeter a(n) is either the long leg or hypotenuse of a triangle whose perimeter is less than a(n).
%C A326309 The long leg and the hypotenuse of a triangle with perimeter a(n) are the short legs of triangles with perimeter greater than a(n).
%C A326309 This sequence is a subsequence of A024364. A subsequence of this sequence exists after applying the restrictions imposed by the sequence title to the sequence itself and begins a(2), a(3), a(9), a(11), ... . Applying the same restrictions on {a(2), a(3), a(9), a(11), ...} gives a sequence a(9), a(11), a(22), a(25), ... .
%C A326309 Question: Does recursive application of this sequence to A024364 terminate?
%e A326309 30 is a term because 30 = 5+12+13 and 12 = 3+4+5 and 84 = 12+35+37 and 182 = 13+84+85.
%e A326309 84 is a term because 84 = 12+35+37 and 30 = 5+12+13 and 1260 = 35+612+613 and 1406 = 37+684+685.
%e A326309 182 is a term because 182 = 13+84+85 and 30 = 5+12+13 and 476 = 84+187+205 and 374 = 85+132+157.
%Y A326309 Subsequence of A024364.
%K A326309 nonn
%O A326309 1,1
%A A326309 _Torlach Rush_, Oct 17 2019