A235396 Indices of primes in the tribonacci-like sequence, A081172.

3, 4, 5, 9, 12, 16, 24, 32, 101, 116, 245, 34553, 52517, 99245, 140197

Offset: 1

Author

Robert Price, Jan 09 2014

Keywords

• nonn

Comments

a(16) > 2*10^5.

Links

• Tony D. Noe and Jonathan Vos Post, Primes in Fibonacci n-step and Lucas n-step Sequences, J. of Integer Sequences, Vol. 8 (2005), Article 05.4.4

Crossrefs

Cf. A001590, A100683, A231574, A231575, A232542, A214899, A230607, A020992, A232498, A214727, A081172, A214752.

Programs

Mathematica

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