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A140140
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Positions of first appearances of odd primes in A137576.
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6
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1, 2, 3, 5, 4, 7, 9, 11, 14, 10, 18, 12, 21, 23, 26, 29, 17, 33, 35, 28, 39, 41, 42, 48, 50, 51, 53, 45, 43, 63, 46, 68, 69, 74, 38, 78, 66, 83, 86, 89, 90, 95, 59, 98, 85, 49, 111, 113, 97, 88, 119, 71, 125, 128, 131, 134, 135, 138, 93, 141, 146, 109, 155, 84, 158, 165, 145
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OFFSET
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1,2
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COMMENTS
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a(n) <= (p_n-1)/2, where p_n is the n-th odd prime (A065091).
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LINKS
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MATHEMATICA
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terms = 100;
a137576[n_] := Module[{t}, (t = MultiplicativeOrder[2, 2 n + 1])* DivisorSum[2 n + 1, EulerPhi[#]/MultiplicativeOrder[2, #] &] - t + 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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EXTENSIONS
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STATUS
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approved
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