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 A246470 Start of the least quadruplet of consecutive squarefree numbers each of which has exactly n distinct prime factors. 3

%I #8 Apr 11 2022 22:21:26

%S 4058471,91,3854,178086,15469622,18230787183

%N Start of the least quadruplet of consecutive squarefree numbers each of which has exactly n distinct prime factors.

%C By "consecutive squarefree numbers" we mean consecutive terms of A005117, not consecutive integers that also happen to be squarefree.

%e 4058471, 4058473, 4058477, and 4058479 are the smallest 4 primes that are also consecutive squarefree numbers (4058472 = 2^3*3*11*15373, 4058474 = 2*7^2*41413, 4058475 = 3*5^2*53*1021, 4058476 = 2^2*19*53401, and 4058478 = 2*3^3*17*4421), so a(1) = 4058471.

%e 91, 93, 94, and 95 are the smallest 4 semiprimes that are also consecutive squarefree numbers, so a(2) = 91.

%e 3854, 3855, 3857, and 3858 is the smallest 4-tuple of consecutive squarefree numbers each of which has exactly 3 prime factors, so a(3) = 3854.

%Y Cf. A005117, A242621 (triple version), A246548 (5-tuple version), A246471.

%K nonn

%O 1,1

%A _Hans Havermann_, Aug 27 2014

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Last modified April 21 01:42 EDT 2024. Contains 371850 sequences. (Running on oeis4.)