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A114529 Let S(n)=sigma(|n|)/2-n; sequence gives numbers n such that S(S(S(S(n))))=n. May be called {1,2}-sociable number of orders 1 or 2 or 4. 3
41, 929, 1301, 30240, 32760, 260609, 1441440, 1860768, 2178540, 3205440, 3378240, 3423420, 3914820, 4029480, 4437720, 5738040, 6093360, 6807240, 7136640, 7239120, 7551360, 9402120, 10204740, 12270720, 12405120, 12942720, 13495680, 14627340, 14725620 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
Eric Weisstein's World of Mathematics, Sociable Numbers
CROSSREFS
Sequence in context: A182359 A090836 A282928 * A300173 A293619 A177418
KEYWORD
nonn
AUTHOR
Yasutoshi Kohmoto, Feb 15 2006
EXTENSIONS
a(7)-a(29) from Charles R Greathouse IV, Nov 12 2010.
STATUS
approved

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Last modified July 17 05:50 EDT 2024. Contains 374360 sequences. (Running on oeis4.)