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 A048295 #20 Jun 12 2019 16:28:51 %S A048295 271,349,3001,10099,11719,12281,25889,39901,46399,63659,169219,250361, %T A048295 264169,287629,289049,312581,353081,440681,473009,502501,502961, %U A048295 541951,594751,620491,627911,632699,704581,757111,762899,922261,959269 %N A048295 Sequence of 3 Pythagorean triangles, each with a leg and hypotenuse prime. The hypotenuse of each triangle is the leg of the next triangle. %H A048295 Ray Chandler, <a href="/A048295/b048295.txt">Table of n, a(n) for n = 1..10000</a> %H A048295 H. Dubner and T. Forbes, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL4/DUBNER/pyth.html">Prime Pythagorean triangles</a>, J. Integer Seqs., Vol. 4 (2001), #01.2.3. %F A048295 For each p(n), q=(p*p+1)/2, r=(q*q+1)/2, s=(r*r+1)/2 and p, q, r, s are all prime. %e A048295 p(5)=271, q=36721, r=674215921, s=227283554064939121. %Y A048295 Cf. A048161, A048270, A308635, A308636. Primes in A188546. %K A048295 nonn %O A048295 1,1 %A A048295 Harvey Dubner (harvey(AT)dubner.com) %E A048295 More terms from _Ray Chandler_, Jun 12 2019