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A134716
a(n) = least number m such that sigma(m)/m > n, where sigma(m) = sum of divisors of m.
4
1, 2, 12, 180, 27720, 122522400, 130429015516800, 1970992304700453905270400, 1897544233056092162003806758651798777216000, 4368924363354820808981210203132513655327781713900627249499856876120704000
OFFSET
0,2
EXAMPLE
Values written as products of primorials:
n a(n)
0 1
1 2
2 2*3#
3 3#*5# (= 180)
4 2*3#*11#
5 8*5#*17#
6 16*3#*7#*29#
7 8*3#*3#*7#*53#
8 32*3#*3#*5#*11#*89#
9 32*3#*3#*7#*17#*157#
10 16*3#*3#*5#*7#*23#*271#
11 16*3#*3#*5#*7#*29#*487#
12 16*3#*3#*5#*7#*13#*31#*857#
CROSSREFS
Cf. A023199 (least k with sigma(k) >= nk)
Sequence in context: A156516 A228593 A067962 * A243807 A006023 A039748
KEYWORD
nonn
AUTHOR
Pierre CAMI, Jan 27 2008, corrected Feb 26 2008 with the help of Emeric Deutsch
EXTENSIONS
More terms can be obtained by expanding the expressions in the example lines. - N. J. A. Sloane, Feb 26 2008
STATUS
approved