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A244930 Indices of primes in A214831. 1
3, 4, 7, 8, 16, 26, 34, 42, 78, 94, 101, 107, 216, 255, 543, 562, 851, 981, 1099, 1528, 1824, 1955, 2122, 2488, 2500, 15331, 15961, 24107, 24938, 26051, 58504, 61617, 81034, 85119, 89768, 90597, 97191, 116899, 195346 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(40) > 2*10^5.

LINKS

Table of n, a(n) for n=1..39.

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

MATHEMATICA

a={1, 9, 9}; For[n=3, n<=1000, n++, sum=Plus@@a; If[PrimeQ[sum], Print[n]]; a=RotateLeft[a]; a[[3]]=sum]

Flatten[Position[LinearRecurrence[{1, 1, 1}, {1, 9, 9}, 200000], _?PrimeQ]]-1 (* The prime number at index 195346 (term a(39) of this sequence) has 51699 digits, so this program takes a long time to run. *) (* Harvey P. Dale, Dec 29 2019 *)

CROSSREFS

Cf. A001590, A100683, A231574, A231575, A232542, A214899, A230607, A020992, A232498, A214727, A081172, A214752, A141523, A214825, A235862, A214827, A214828, A214829, A243622, A243623, A214831.

Sequence in context: A219019 A306612 A117587 * A130420 A214096 A169943

Adjacent sequences:  A244927 A244928 A244929 * A244931 A244932 A244933

KEYWORD

nonn

AUTHOR

Robert Price, Jul 08 2014

STATUS

approved

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Last modified October 16 20:36 EDT 2021. Contains 348047 sequences. (Running on oeis4.)