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 A246470 Start of the least quadruplet of consecutive squarefree numbers each of which has exactly n distinct prime factors. 3
 4058471, 91, 3854, 178086, 15469622, 18230787183 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS By "consecutive squarefree numbers" we mean consecutive terms of A005117, not consecutive integers that also happen to be squarefree. LINKS EXAMPLE 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. 91, 93, 94, and 95 are the smallest 4 semiprimes that are also consecutive squarefree numbers, so a(2) = 91. 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. CROSSREFS Cf. A005117, A242621 (triple version), A246548 (quintuplet version), A246471. Sequence in context: A104930 A251614 A187599 * A231614 A191346 A307846 Adjacent sequences:  A246467 A246468 A246469 * A246471 A246472 A246473 KEYWORD nonn AUTHOR Hans Havermann, Aug 27 2014 STATUS approved

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Last modified January 27 12:47 EST 2021. Contains 340465 sequences. (Running on oeis4.)