Largest side lengths of almost-equilateral Heronian triangles.

Terms

a(0) =5a(1) =15a(2) =53a(3) =195a(4) =725a(5) =2703a(6) =10085a(7) =37635a(8) =140453a(9) =524175a(10) =1956245a(11) =7300803a(12) =27246965a(13) =101687055a(14) =379501253a(15) =1416317955a(16) =5285770565a(17) =19726764303a(18) =73621286645a(19) =274758382275