OFFSET
1,1
COMMENTS
REFERENCES
S. Ramanujan, Highly composite numbers, Proc. London Math. Soc., 14 (1915), 347-407. Reprinted in Collected Papers, Ed. G. H. Hardy et al., Cambridge 1927; Chelsea, NY, 1962, pp. 78-129. See esp. pp. 87, 115.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..3401 (calculated using the b-file at A000705)
S. Ramanujan, Highly Composite Numbers.
FORMULA
a(n) = a(n-1) * (1 + 1/k(n)), where k(n) is the p(n)-adic valuation of the n-th superior highly composite number N(n), with p(n) = N(n)/N(n-1) and N(0)=1.
EXAMPLE
a(8)=60 because the eighth superior highly composite number, 5040, has 60 divisors.
CROSSREFS
KEYWORD
nonn
AUTHOR
David Terr, Oct 14 2004
STATUS
approved