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A359685
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Greatest prime dividing 2^n + n.
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1
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3, 3, 11, 5, 37, 7, 5, 11, 521, 47, 71, 79, 547, 911, 32783, 241, 307, 6899, 24967, 87383, 457, 4799, 270601, 7109, 3728273, 12497, 1201, 100613, 2017, 17318417, 859, 87211, 47491, 8589934609, 195329, 1483453, 320370521, 8191129, 549755813927, 478881371
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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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a:= n-> max(numtheory[factorset](2^n+n)):
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MATHEMATICA
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a[n_] := FactorInteger[2^n + n][[-1, 1]]; Array[a, 40] (* Amiram Eldar, Mar 30 2023 *)
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PROG
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(PARI) a(n) = vecmax(factor(2^n+n)[, 1]); \\ Michel Marcus, Jan 11 2023
(Python)
from sympy import primefactors
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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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