A233554 - OEIS

%I #5 Dec 12 2013 22:37:53

%S 1,3,6,15,19,22,207,542,2374,10579,17726,43182

%N Indices of primes in the tribonacci-like sequence, A020992.

%C a(13) > 2*10^5.

%t a={0,2,1};Print[1];For[n=3,n<=1000,n++,sum=Plus@@a;If[PrimeQ[sum],Print[n]];a=RotateLeft[a]; a[[3]]=sum]

%Y Cf. A001590, A100683, A231574, A231575, A232542, A214899, A230607, A020992, A232498.

%K nonn

%O 1,2

%A _Robert Price_, Dec 12 2013