login
A233554
Indices of primes in the tribonacci-like sequence, A020992.
20
1, 3, 6, 15, 19, 22, 207, 542, 2374, 10579, 17726, 43182
OFFSET
1,2
COMMENTS
a(13) > 2*10^5.
MATHEMATICA
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]
KEYWORD
nonn
AUTHOR
Robert Price, Dec 12 2013
STATUS
approved