

A104577


Indices of prime generalized tetranacci numbers, A073817.


5



2, 3, 8, 9, 16, 19, 24, 27, 46, 68, 71, 78, 107, 198, 309, 377, 477, 1057, 1631, 2419, 3974, 4293, 8247, 10513, 10709, 12011, 15042, 30543, 31607, 39664, 47552, 145858
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OFFSET

1,1


COMMENTS

The sequence of generalized tetranacci numbers is defined as beginning with 1, 3, 7, 15. Subsequent terms are the sum of the previous four terms. Note that the sequence of these generalized tetranacci numbers has many more primes than the tetranacci sequence A000078 (whose prime indices are in A104534).


LINKS



MATHEMATICA

a={1, 1, 1, 4}; Do[s=Plus@@a; a=RotateLeft[a]; a[[4]]=s; If[PrimeQ[s], Print[n]], {n, 30000}]


CROSSREFS

Cf. A104576 (indices of prime generalized tribonacci numbers).


KEYWORD

nonn


AUTHOR



STATUS

approved



