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A210488
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a(n) is the index of A210487 when the n-th prime appears for the first time.
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1
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3, 4, 2, 20, 60, 92, 246, 752, 1289, 2084, 3383
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OFFSET
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1,1
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LINKS
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EXAMPLE
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3 appears for the first time as A210487(4), so a(2)=4;
5 appears for the first time as A210487(2), so a(3)=2.
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MAPLE
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N := 60 ;
for n from 2 do
if isprime(a) then
idx := numtheory[pi](a) ;
if idx <= N then
end if;
end if;
end if;
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MATHEMATICA
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nn = 11; a = Table[0, {nn}]; k = 1; While[Times @@ a == 0, k++; p1 = Prime[k]; id = PrimePi[Min[Table[Last[FactorInteger[Prime[k]^2 - Prime[j]^2]][[1]], {j, k - 1}]]]; If[id <= nn && a[[id]] == 0, a[[id]] = k]]; a
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CROSSREFS
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KEYWORD
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nonn,hard
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AUTHOR
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STATUS
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approved
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