A138605 - OEIS

%I #5 Jan 22 2020 10:14:56

%S 204,228,276,280,300,315,336,348,372,385,420,429,444,455,492,495,504,

%T 516,540,555,560,564,580,585,588,615,616,620,636,645,660,693,696,705,

%U 708,715,720,732,735,740,744,765,780,792,795,804,819,820

%N Short legs of more than 3 primitive Pythagorean triangles.

%H Ray Chandler, <a href="/A138605/b138605.txt">Table of n, a(n) for n = 1..10000</a>

%e Some examples:

%e 444,1333,1405; 444,5467,5485; 444,12317,12325; 444,49283,49285;

%e 429, 460, 629; 429, 700, 821; 429,10220,10229; 429,92020,92021;

%e 420, 851, 949; 420,1189,1261; 420, 1739, 1789; 420,4891,4909; 420,11021,11029; 420,44099,44101;

%e 385,552,673; 385,1488,1537; 385,2952,2977; 385,74112,74113;

%e 372,925,997; 372,3835,3853; 372,8645,8653; 372,34595,34597;

%e 348,805,877; 348,3355,3373; 348,7565,7573; 348,30275,30277;

%e 336,377,505; 336,527,625; 336,3127,3145; 336,28223,28225;

%e 315,572,653; 315,988,1037; 315,1972,1997; 315,49612,49613;

%e 300,589,661; 300,2491,2509; 300,5621,5629; 300,22499,22501;

%e 280,351,449; 280,759,809; 280,1209,1241; 280,19599,19601;

%e 276,493,565; 276,2107,2125; 276,4757,4765; 276,19043,19045;

%e 228,325,397; 228,1435,1453; 228,3245,3253; 228,12995,12997;

%e 204,253,325; 204,1147,1165; 204,2597,2605; 204,10403,10405;...

%t lst={}; aa=aaa=aaaa=1; For[ a=204,a<=10^3-100,For[ b=a+1,((b+1)^2-b^2)<=a^2,c=(a^2+b^2)^0.5; If[ c==Round[ c ]&&GCD[ a,b ]==1,If[ a==aaaa,Print[ a ]; AppendTo[ lst,a ] ]; aaaa=aaa; aaa=aa; aa=a; ]; b=b+2 ]; a++ ]; Union[ lst ]

%K nonn

%O 1,1

%A _Vladimir Joseph Stephan Orlovsky_, May 13 2008, revised Apr 20 2010