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A183071 Positive integers k such that each prime divisor of 2^k - 1 has the form 4j + 3. 8
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 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
The exponents of the Mersenne primes (A000043) are contained in this sequence.
Needed factorizations are in the Cunningham Project.
LINKS
S. S. Wagstaff, Jr., The Cunningham Project.
FORMULA
A183075(n) = 2^a(n) - 1.
EXAMPLE
6 is in this sequence because 2^6 - 1 = 3^2 * 7, and 3 and 7 have the form 4j + 3.
CROSSREFS
Sequence in context: A298705 A030051 A344308 * A139826 A358374 A182048
KEYWORD
nonn
AUTHOR
Stuart Clary, Dec 23 2010
EXTENSIONS
a(53)-a(54) from Amiram Eldar, Feb 18 2019
STATUS
approved

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Last modified March 18 22:09 EDT 2024. Contains 370951 sequences. (Running on oeis4.)