A355812 - OEIS

%I #11 Jul 18 2022 22:49:38

%S 35,55,56,63,70,72,80,85,90,105,110,112,117,120,126,140,144,152,154,

%T 156,160,165,168,170,175,176,180,182,189,203,208,210,216,220,221,224,

%U 231,234,240,245,252,255,270,275,280,286,288,297,304,306,308,312,315,320,330,336

%N Values t of the solutions to 1/s^2 + 1/t^2 = 1/p^2 + 1/q^2 where p,q < t.

%H Jianing Song, <a href="/A355812/b355812.txt">Table of n, a(n) for n = 1..307</a> (all terms <= 1500)

%e 1/5^2 + 1/35^2 = 1/7^2 + 1/7^2, so 35 is a term.

%e 1/10^2 + 1/55^2 = 1/11^2 + 1/22^2, so 55 is a term.

%o (PARI) isA355812(n) = for(p=1, n-1, for(q=1, n-1, r=1/(1/p^2+1/q^2-1/n^2); if(r==r\1 && issquare(r), return(1)))); return(0)

%Y Cf. A355813, A355814.

%K nonn

%O 1,1

%A _Jianing Song_, Jul 18 2022