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%I #11 Nov 18 2013 16:37:07
%S 2,6,30,351137972965951,8596208716179446431,
%T 698211042943963834650959743951,744014385572130806167897354113929551,
%U 901203402294977554329263775346819632824908852456695769189267773301
%N a(n) = the smallest squarefree number (A005117) with n prime factors in a 2p-1 progression.
%C Smallest squarefree numbers with n >= 2 prime divisors of the form p_1 * p_2 * … * p_n, where p_1 < p_2 < … < p_k = primes with p_k = 2 * p_(k-1) - 1.
%C Subsequence of A231814.
%H Jaroslav Krizek, <a href="/A231816/b231816.txt">Table of n, a(n) for n = 1..15</a>
%e 8596208716179446431 = 1531*3061*6121*12241*24481, where 3061 = 2*1531 - 1, 6121 = 2*3061 - 1, 12241 = 2*6121 - 1, 24481 = 2*12241 - 1.
%Y Cf. A005117, A000040, A231814, A231815.
%Y Cf. A057330 (first prime for such numbers that has n factors).
%K nonn
%O 1,1
%A _Jaroslav Krizek_, Nov 13 2013
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