OFFSET
1,7
COMMENTS
Length of row n of A212184 equals a(n) if a(n) is positive, 1 otherwise.
REFERENCES
S. Ramanujan, Highly composite numbers, Proc. Lond. Math. Soc. 14 (1915), 347-409; reprinted in Collected Papers, Ed. G. H. Hardy et al., Cambridge 1927; Chelsea, NY, 1962.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
A. Flammenkamp, List of the first 1200 highly composite numbers
S. Ramanujan, Highly Composite Numbers
EXAMPLE
The canonical prime factorization of 720 (2^4*3^2*5) has 2 exponents that equal or exceed 2. Since 720 = A002182(14), a(14) = 2.
MATHEMATICA
s={}; dm=0; Do[d = DivisorSigma[0, n]; If[d > dm, dm = d; e = FactorInteger[n][[;; , 2]]; AppendTo[s, Count[e, _?(# > 1 &)]]], {n, 1, 10^6}]; s (* Amiram Eldar, Jun 30 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Matthew Vandermast, Jul 16 2012
STATUS
approved