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A119240
Least odd number k such that sigma(k)/k >= n.
12
1, 945, 1018976683725, 1853070540093840001956842537745897243375
OFFSET
1,2
COMMENTS
These numbers are a subset of the oddly superabundant numbers, A119239. Laatsch mentions a(3). Pettigrew computes a(4) and a(5), the latter being a 123-digit number.
Pettigrew (link, Tableau 5, p. 21) gives a(5) as 3^6*5^4*7^3*11^2*13^2*17^2*19*...*277. - Jeppe Stig Nielsen, Jul 03 2017
LINKS
Jeppe Stig Nielsen, Table of n, a(n) for n = 1..5
Richard Laatsch, Measuring the abundancy of integers, Mathematics Magazine 59 (2) (1986) 84-92.
Steve Pettigrew, Sur la distribution de nombres spéciaux consécutifs, M.Sc. Thesis, Univ. Laval, 2000.
CROSSREFS
Cf. A023199 (least number k such that sigma(k)/k >= n).
Sequence in context: A133353 A322252 A351806 * A257722 A093247 A248785
KEYWORD
nonn
AUTHOR
T. D. Noe, May 09 2006
STATUS
approved