

A003416


Sociable numbers: smallest member of each cycle.


7



12496, 14316, 1264460, 2115324, 2784580, 4938136, 7169104, 18048976, 18656380, 28158165, 46722700, 81128632, 174277820, 209524210, 330003580, 498215416, 805984760, 1095447416, 1236402232, 1276254780, 1799281330
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OFFSET

1,1


COMMENTS

Numbers belonging to aliquot cycles of length greater than 2.
The lengths of the corresponding aliquot cycles are given by A052470.  Michel Marcus, Nov 15 2013


REFERENCES

R. K. Guy, Unsolved Problems Number Theory, B7.
P. Poulet, Parfaits, amiables et extensions, Editions Stevens, Bruxelles, 1918.
D. Wells, The Penguin Dictionary of Curious and Interesting Numbers, pp. 174 Penguin Books 1987.


LINKS

Table of n, a(n) for n=1..21.
INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 112
D. Moews, Perfect, amicable and sociable numbers
D. Moews, Sociable numbers
J. O. M. Pedersen, Tables of Aliquot Cycles
Eric Weisstein's World of Mathematics, Sociable Numbers.


CROSSREFS

Cf. A072890, A072891.
Sequence in context: A232104 A122726 A072891 * A178278 A220026 A231956
Adjacent sequences: A003413 A003414 A003415 * A003417 A003418 A003419


KEYWORD

nonn,nice


AUTHOR

N. J. A. Sloane.


EXTENSIONS

Incorrect g.f. deleted by N. J. A. Sloane, Sep 20 2008


STATUS

approved



