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A135955
(Nonprime Fibonacci numbers with prime indices, A050937) which have exactly 4 prime factors.
7
83621143489848422977, 6161314747715278029583501626149, 289450641941273985495088042104137, 5193981023518027157495786850488117, 66233869353085486281758142155705206899077
OFFSET
1,1
COMMENTS
Conjecture: All numbers in this sequence are products of four sums of two squares.
MATHEMATICA
k = {}; Do[If[ !PrimeQ[Fibonacci[Prime[n]]], c = Length[FactorInteger[Fibonacci[Prime[n]]]]; If[c == 4, AppendTo[k, Fibonacci[Prime[n]]]]], {n, 1, 50}]; k
KEYWORD
nonn
AUTHOR
Artur Jasinski, Dec 08 2007
STATUS
approved