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A133247
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Prime numbers p with property that no odd Fibonacci number is divisible by p.
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5
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2, 17, 19, 23, 31, 53, 61, 79, 83, 107, 109, 137, 167, 173, 181, 197, 211, 227, 229, 241, 257, 271, 293, 317, 349, 379, 383, 409, 421, 439, 443, 467, 499, 503, 541, 571, 587, 593, 601, 617, 631, 647, 653, 683, 691, 739, 751, 769, 773, 797, 811, 827, 829, 857
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OFFSET
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1,1
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COMMENTS
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The Mathematica coding uses the fact that the Pisano period - the period with which a Fibonacci sequence (mod n) repeats itself is not more than 6n and the fact that the Fibonacci sequence starts with 0.
Subsequence of A133246 except for 2.
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LINKS
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MAPLE
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filter:= proc(p) local a, b, i;
if not isprime(p) then return false fi;
a:= 0: b:= 1;
for i from 2 do
a, b:= b, (a+b) mod p;
if b = 0 then
if i mod 3 <> 0 then return false
elif a = 1 then return true
fi
fi
od:
end proc:
select(filter, [2, seq(i, i=3..1000, 2)]); # Robert Israel, Nov 20 2016
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MATHEMATICA
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Transpose[ Select[Table[{Prime[m], Select[Table[{n, Mod[Fibonacci[n], Prime[m]]}, {n, 6Prime[m] + 1}], Mod[ #[[1]], 3] != 0 && #[[2]] == 0 &]}, {m, 300}], #[[2]] == {} &]][[1]]
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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