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A302490 Fewest number of distinct prime factors in any product of a_1*a_2*...*a_t where n = a_1 < a_2 < ... < a_t = A006255(n) and the product is square. 0
0, 2, 2, 1, 2, 2, 2, 3, 1, 3, 3, 3, 3, 4, 3, 1, 2, 2, 2, 3, 3, 3, 2, 2, 1, 3, 4, 3, 2, 4, 2, 3, 5, 4, 4, 2, 3, 3, 3, 3, 3, 3, 3, 4, 3, 3, 3, 3, 1, 4, 4, 5, 3, 4, 5, 3, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
a(n^2) = A001221(n).
LINKS
EXAMPLE
a(14) = 4 because 14 * 15 * 16 * 18 * 20 * 21 has four distinct prime factors (2, 3, 5, and 7) and no other square product of a strictly increasing sequence starting at 14 and ending at 21 has fewer distinct prime factors.
CROSSREFS
Sequence in context: A198260 A029350 A166597 * A316841 A000003 A234398
KEYWORD
nonn,more
AUTHOR
Peter Kagey, Apr 08 2018
STATUS
approved

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Last modified March 19 04:26 EDT 2024. Contains 370952 sequences. (Running on oeis4.)