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A140140 Positions of first appearances of odd primes in A137576. 6
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 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
a(n) <= (p_n-1)/2, where p_n is the n-th odd prime (A065091).
LINKS
MATHEMATICA
terms = 100;
a137576[n_] := Module[{t}, (t = MultiplicativeOrder[2, 2 n + 1])* DivisorSum[2 n + 1, EulerPhi[#]/MultiplicativeOrder[2, #] &] - t + 1];
A137576 = Array[a137576, 3 terms];
FirstPosition[A137576, #][[1]]& /@ Prime[Range[2, terms+1]] (* Jean-François Alcover, Jan 11 2019 *)
CROSSREFS
Sequence in context: A249064 A257489 A090252 * A242693 A119474 A308098
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, May 10 2008
EXTENSIONS
Corrected and extended by Ray Chandler, May 19 2008
STATUS
approved

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Last modified March 29 06:57 EDT 2024. Contains 371265 sequences. (Running on oeis4.)