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, 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

Links

Table of n, a(n) for n=1..50.

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

Cf A002182.

Sequence in context: A286216 A280727 A232357 * A307186 A060784 A181204

Adjacent sequences: A196299 A196300 A196301 * A196303 A196304 A196305

Keyword

nonn

Author

J. Lowell, Sep 30 2011

Status

approved