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A196302
Smallest highly composite number that is not a divisor of n-th highly composite number or 0 if no such number exists.
0
0, 0, 0, 4, 0, 0, 24, 36, 24, 36, 24, 36, 48, 0, 36, 24, 36, 48, 0, 48, 7560, 10080, 7560, 7560, 48, 10080, 7560, 7560, 48, 7560, 10080, 7560, 7560, 20160, 10080, 7560, 25200, 7560, 48, 7560, 10080, 7560, 7560, 20160, 10080, 7560, 25200, 10080, 7560, 25200
OFFSET
1,4
COMMENTS
a(19) is the last 0 in this sequence
EXAMPLE
a(4) = 4 because 6, the fourth highly composite number, is a multiple of 1 and 2 but not of 4. a(5) = 0 because 12 is a multiple of all of 1, 2, 4, 6, and 12.
MATHEMATICA
(* let hc contain consecutive highly composite numbers starting with 1 *) Table[i = 1; While[i < n && Mod[hc[[n]], hc[[i]]] == 0, i++]; If[i == n, 0, hc[[i]]], {n, Length[hc]}] (* T. D. Noe, Sep 30 2011 *)
CROSSREFS
Sequence in context: A286216 A280727 A232357 * A307186 A060784 A181204
KEYWORD
nonn
AUTHOR
J. Lowell, Sep 30 2011
STATUS
approved