Number of twin Pythagorean triples with hypotenuse less than 10^n.

Terms

a(0) =1a(1) =7a(2) =24a(3) =74a(4) =228a(5) =712a(6) =2243a(7) =7079a(8) =22370a(9) =70722a(10) =223619a(11) =707120a(12) =2236083a(13) =7071084a(14) =22360697a(15) =70710696a(16) =223606818a(17) =707106802a(18) =2236067999a(19) =7071067836a(20) =22360679800a(21) =70710678145a(22) =223606797778a(23) =707106781216