OFFSET
1,2
COMMENTS
a(n) = maximal number of members of A002182 that have a least common multiple of A181804(n). Also, a(n) = length of row A181804(n) in triangles A181802 and A181803.
4, 13 and 16 are the first three positive integers that appear nowhere in this sequence (and, therefore, nowhere in A181801). It would be interesting to know whether there are others.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Achim Flammenkamp, List of the first 1200 highly composite numbers.
Eric Weisstein's World of Mathematics, Highly composite number.
EXAMPLE
MATHEMATICA
seq[max_] := Module[{hcn = {}, hcnmax, d, dm = 0, s = {1}}, Do[d = DivisorSigma[0, n]; If[d > dm, dm = d; AppendTo[hcn, n]], {n, 1, max}]; hcnmax = hcn[[-1]]; Do[s = Union[Join[s, Select[LCM[hcn[[k]], s], # <= hcnmax &]]], {k, 2, Length[hcn]}]; Do[s[[k]] = Count[hcn, _?(Divisible[s[[k]], #] &)], {k, 1, Length[s]}]; s]; seq[300000] (* Amiram Eldar, Jun 23 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Matthew Vandermast, Nov 27 2010
EXTENSIONS
More terms from Amiram Eldar, Jun 23 2023
STATUS
approved