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A336943
Least prime factor of 44745755^4 + 2^(4n+2).
2
797, 37, 13, 113, 29, 13, 73, 2593, 13, 41, 37, 13, 509, 57881, 13, 73, 293, 13, 29, 37, 13, 7555049, 53, 13, 41, 29, 13, 677, 37, 13, 8557781, 113, 13, 73, 41, 13, 397, 37, 13, 29, 1217, 13, 73, 9820301, 13, 113, 29, 13, 53, 41, 13, 73, 113, 13, 41, 37, 13
OFFSET
0,1
COMMENTS
k = 44745755^4 has the property that k + 2^m is composite for all m. However, it is conjectured that this sequence is unbounded. This is the case if and only if A336347 is unbounded; because a full covering set for k*2^m + 1 would also be a full covering for k + 2^m, and vice versa.
LINKS
M. Filaseta et al., On powers associated with Sierpiński numbers, Riesel numbers and Polignac's conjecture, Journal of Number Theory, Volume 128, Issue 7 (July 2008), pp. 1916-1940.
Anatoly S. Izotov, A Note on Sierpinski Numbers, Fibonacci Quarterly (1995), pp. 206-207.
PROG
(PARI) a(n) = vecmin(factor(44745755^4+2^(4*n+2))[, 1]); \\ Michel Marcus, Aug 08 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Jeppe Stig Nielsen, Aug 08 2020
STATUS
approved