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 A114528 Let S(n)=sigma(|n|)-3*n; sequence gives numbers n such that S(S(S(S(n))))=n. May be called {3,1}-Sociable number of orders 1 or 2 or 4. 2
 1248, 1596, 28272, 30240, 32760, 463296, 678032, 1906128, 2178540, 4694328, 4697616, 4698072, 11110976, 12865770, 23569920, 30998250, 31235904, 37501072, 45532800, 63723600, 76980288, 95801088, 142990848, 146078592, 163032720, 614533696, 1044244800, 1379454720 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..28. Eric Weisstein's World of Mathematics, Sociable Numbers PROG (PARI) S(n)=sigma(abs(n))-3*n is(n)=S(S(S(S(n))))==n \\ Charles R Greathouse IV, Jan 16 2012 CROSSREFS Cf. A113285, A114529. Contains A069146 as a subsequence. Sequence in context: A252675 A066696 A195006 * A069146 A251648 A235021 Adjacent sequences: A114525 A114526 A114527 * A114529 A114530 A114531 KEYWORD nonn AUTHOR Yasutoshi Kohmoto, Feb 15 2006 EXTENSIONS a(5)-a(12) from Charles R Greathouse IV, Jan 20 2010 a(13)-a(28) from Donovan Johnson, Jan 16 2012 STATUS approved

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Last modified July 12 06:35 EDT 2024. Contains 374237 sequences. (Running on oeis4.)