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A076565
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Greatest prime divisor of 2n+1 (sum of two successive integers).
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6
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3, 5, 7, 3, 11, 13, 5, 17, 19, 7, 23, 5, 3, 29, 31, 11, 7, 37, 13, 41, 43, 5, 47, 7, 17, 53, 11, 19, 59, 61, 7, 13, 67, 23, 71, 73, 5, 11, 79, 3, 83, 17, 29, 89, 13, 31, 19, 97, 11, 101, 103, 7, 107, 109, 37, 113, 23, 13, 17, 11, 41, 5, 127, 43, 131, 19, 5, 137, 139, 47, 13
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OFFSET
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1,1
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LINKS
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FORMULA
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MAPLE
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seq(max(numtheory:-factorset(2*n+1)), n=1..200); # Robert Israel, Mar 17 2017
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MATHEMATICA
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Table[FactorInteger[2n + 1][[-1, 1]], {n, 1, 100}] (* Indranil Ghosh, Mar 20 2017 *)
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PROG
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(PARI) for(n=1, 100, print1(vecmax(factor(2*n + 1)[, 1]), ", ")) \\ Indranil Ghosh, Mar 20 2017
(Python)
from sympy.ntheory import primefactors
print([max(primefactors(2*n + 1)) for n in range(1, 101)]) # Indranil Ghosh, Mar 20 2017
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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