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A183076 Composite numbers of the form 2^k - 1 for which each prime divisor has the form 4j + 3. 8
63, 1023, 16383, 32767, 67108863, 1073741823, 17179869183, 274877906943, 8796093022207, 2251799813685247, 4611686018427387903, 36893488147419103231 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Needed factorizations are in the Cunningham Project.
LINKS
S. S. Wagstaff, Jr., The Cunningham Project.
FORMULA
a(n) = 2^A183072(n) - 1.
EXAMPLE
63 = 2^6 - 1 = 3^2 * 7, and 3 and 7 have the form 4j + 3.
CROSSREFS
Sequence in context: A112494 A258004 A258014 * A230660 A132465 A202983
KEYWORD
nonn,hard
AUTHOR
Stuart Clary, Dec 23 2010
STATUS
approved

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Last modified June 13 22:21 EDT 2024. Contains 373391 sequences. (Running on oeis4.)