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A291360
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Prime divisors of 2^720 - 1.
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3
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3, 5, 7, 11, 13, 17, 19, 31, 37, 41, 61, 73, 97, 109, 151, 181, 241, 257, 331, 433, 577, 631, 673, 1321, 23311, 38737, 54001, 61681, 8369281, 18837001, 29247661, 394783681, 4278255361, 4562284561, 46908728641, 168692292721, 487824887233, 469775495062434961, 750016890283777055704738227247474485366338380663681
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OFFSET
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1,1
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COMMENTS
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It is possible to find an odd positive integer k and a set S = {p(1), ..., p(s)} containing only primes which appeared in the sequence such that for any nonnegative integer n, k*2^n + 1 == 0 (mod p(i)) and k*2^n - 1 == 0 (mod p(j)) for some p(i) and some p(j) from the set S.
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LINKS
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MATHEMATICA
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Select[Divisors[2^720-1], PrimeQ]
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PROG
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(Magma) PrimeDivisors(2^720-1);
(PARI) forprime(p=1, , if(Mod(2, p)^720==1, print1(p, ", "))) \\ Felix Fröhlich, Aug 23 2017
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CROSSREFS
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KEYWORD
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nonn,easy,fini,full
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AUTHOR
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STATUS
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approved
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