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 A260867 Least k > 1 that divides A260868(n) + 2^k - 2. 0

%I

%S 35,161,55,35,115,35,115,35,77,209,473,253,55,77,35,235,247,55,35,35,

%T 899,119,1003,415,143,35,335,95,299,497,203,575,35,247,323,95,77,437,

%U 901,35,55,473,35,1457,77,55,517,35,235,493,161,535,209,115,95,1067,689,323,35,1199,1313,355,77,815,635,869,235,119,551,55,115

%N Least k > 1 that divides A260868(n) + 2^k - 2.

%C For all numbers N not listed in A260868, the least k > 1 that divides N + 2^k - 2 is equal to the least prime factor of N.

%C It appears that the range of this sequence is A267999. For example, 155 occurs first somewhat late for N = 2729. - Corrected by _Thomas Ordowski_, Oct 27 2018

%o (PARI) my(aa(n)=for(k=2,9e9,Mod(2,k)^k+n-2||return(k)));for(n=2,1e5,aa(n)==factor(n)[1,1]||print1(aa(n)","))

%K nonn

%O 1,1

%A _M. F. Hasler_, Aug 11 2015

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Last modified February 25 09:44 EST 2020. Contains 332221 sequences. (Running on oeis4.)