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A183071
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Positive integers k such that each prime divisor of 2^k - 1 has the form 4j + 3.
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8
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1, 2, 3, 5, 6, 7, 10, 13, 14, 15, 17, 19, 26, 30, 31, 34, 38, 43, 51, 61, 62, 65, 79, 85, 86, 89, 93, 95, 107, 122, 127, 129, 130, 133, 158, 170, 193, 254, 255, 301, 311, 331, 349, 389, 445, 521, 557, 577, 579, 607, 631, 647, 1103, 1167
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OFFSET
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1,2
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COMMENTS
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The exponents of the Mersenne primes (A000043) are contained in this sequence.
Needed factorizations are in the Cunningham Project.
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LINKS
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FORMULA
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EXAMPLE
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6 is in this sequence because 2^6 - 1 = 3^2 * 7, and 3 and 7 have the form 4j + 3.
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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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