Triangular matchstick numbers in the class of prime numbers: sum of n-th and next n primes.

Terms

a(0) =5a(1) =15a(2) =36a(3) =67a(4) =112a(5) =169a(6) =240a(7) =323a(8) =424a(9) =539a(10) =662a(11) =803a(12) =964a(13) =1133a(14) =1312a(15) =1523a(16) =1746a(17) =1987a(18) =2246a(19) =2519a(20) =2808a(21) =3119a(22) =3436a(23) =3787a(24) =4154a(25) =4529a(26) =4920a(27) =5337a(28) =5770a(29) =6219