Numbers k such that sigma(k) plus the k-th prime is a triangular number.

Terms

a(0) =1a(1) =2a(2) =9a(3) =13a(4) =21a(5) =80a(6) =112a(7) =129a(8) =147a(9) =225a(10) =308a(11) =349a(12) =1063a(13) =1282a(14) =1300a(15) =1635a(16) =1880a(17) =2686a(18) =2956a(19) =3517a(20) =3759a(21) =3907a(22) =4058a(23) =5025a(24) =5196a(25) =6742a(26) =7606a(27) =7708a(28) =9244a(29) =10154