Triangular numbers that are the sum of two distinct nonzero triangular numbers in exactly two ways.

Terms

a(0) =231a(1) =1081a(2) =1225a(3) =1431a(4) =1711a(5) =2556a(6) =5356a(7) =7381a(8) =7875a(9) =8256a(10) =15931a(11) =19306a(12) =20706a(13) =26106a(14) =30381a(15) =33153a(16) =36856a(17) =46056a(18) =51681a(19) =75078a(20) =78606a(21) =102831a(22) =104653a(23) =135981a(24) =149331a(25) =153181a(26) =182106a(27) =197506a(28) =225456a(29) =263175