Triangular numbers that are the product of two distinct prime numbers of the form 4*k + 3.

Terms

a(0) =21a(1) =253a(2) =1081a(3) =13861a(4) =34453a(5) =64261a(6) =73153a(7) =114481a(8) =126253a(9) =258121a(10) =351541a(11) =371953a(12) =392941a(13) =482653a(14) =869221a(15) =933661a(16) =1034641a(17) =1104841a(18) =1660753a(19) =2077741a(20) =2126953a(21) =2434321a(22) =2992681a(23) =4142881a(24) =4212253a(25) =4495501a(26) =4567753a(27) =4862521a(28) =5013361a(29) =6561253