Indices of primes in the tribonacci-like sequence, A214825.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =6a(6) =7a(7) =10a(8) =16a(9) =17a(10) =26a(11) =32a(12) =104a(13) =109a(14) =120a(15) =133a(16) =312a(17) =546a(18) =608a(19) =2274a(20) =2527a(21) =2932a(22) =4462a(23) =4680a(24) =6001a(25) =7103a(26) =17402a(27) =17874a(28) =20664a(29) =26341