

A104576


Indices of prime generalized tribonacci numbers, A001644.


6



2, 3, 4, 7, 8, 9, 10, 12, 20, 30, 33, 66, 76, 77, 82, 87, 98, 180, 205, 360, 553, 719, 766, 1390, 1879, 1999, 4033, 5620, 16506, 17436, 23676, 24428, 27758, 31932, 58199, 67661, 85040, 102023, 185595
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OFFSET

1,1


COMMENTS

The sequence of generalized tribonacci numbers is defined as beginning with 1, 3, 7. Subsequent terms are the sum of the previous three terms. Note that the sequence of these generalized tribonacci numbers has many more primes than the tribonacci sequence A000073 (whose prime indices are in A092835).
a(40) > 2*10^5.  Robert Price, Dec 24 2013


LINKS

Table of n, a(n) for n=1..39.
Tony D. Noe and Jonathan Vos Post, Primes in Fibonacci nstep and Lucas nstep Sequences, J. of Integer Sequences, Vol. 8 (2005), Article 05.4.4


CROSSREFS

Cf. A104577 (indices of prime generalized tetranacci numbers).
Sequence in context: A231003 A171551 A096199 * A031477 A047227 A317047
Adjacent sequences: A104573 A104574 A104575 * A104577 A104578 A104579


KEYWORD

nonn


AUTHOR

T. D. Noe, Mar 16 2005


EXTENSIONS

a(37)a(39) from Robert Price, Dec 24 2013


STATUS

approved



