Numbers of the form prime(n) + prime(n+1) - 2 that are also triangular numbers, T(k) = k(k+1)/2.

Terms

a(0) =3a(1) =6a(2) =10a(3) =28a(4) =66a(5) =136a(6) =666a(7) =1540a(8) =2278a(9) =3160a(10) =3486a(11) =4186a(12) =5050a(13) =6328a(14) =8128a(15) =9730a(16) =11476a(17) =13366a(18) =15400a(19) =16110a(20) =24090a(21) =24976a(22) =27730a(23) =29646a(24) =32896a(25) =37950a(26) =39340a(27) =46360a(28) =69378a(29) =76636