This site is supported by donations to The OEIS Foundation.

 Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS". Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A125490 Amicable triples: numbers such that sigma(x) = sigma(y) = sigma(z) = x+y+z, x
 1980, 9180, 21168, 23940, 37380, 38940, 38940, 39480, 46368, 47124, 53088, 57420, 66720, 67860, 69720, 73320, 75180, 77490, 72072, 86040, 93456, 96660, 92820, 100980, 100980, 112140, 118944, 121800, 139080, 141372 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS G. Resta computed these terms. As stated, we first order by common sigma value. When the common value of sigma is the same for several triples, these are then sorted (ascending) by the smallest member. When the smallest members also agree, we go on to the second smallest members, and so on, lexicographically. - John Cerkan, Jun 18 2016 LINKS John Cerkan, Table of n, a(n) for n = 1..10000 [Terms 1 through 1000 were computed by Donovan Johnson] EXAMPLE 1980 is in the sequence since sigma(1980) = sigma(2016) = sigma(2556) = 6552 = 1980 + 2016 + 2556. - Michael B. Porter, Jun 29 2016 CROSSREFS Cf. A125491, A125492, A137231 (x+y+z). Cf. A036471 - A036474 and A116148 (amicable quadruples). Cf. A233553 for amicable 5-tuples. Cf. A000203 (sigma function). Sequence in context: A108510 A225235 A289907 * A237334 A035870 A252693 Adjacent sequences:  A125487 A125488 A125489 * A125491 A125492 A125493 KEYWORD nonn AUTHOR Yasutoshi Kohmoto, Dec 11 2006 EXTENSIONS Definition corrected by N. J. A. Sloane, Nov 27 2008 a(13)-a(30) from Donovan Johnson, Apr 14 2010 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.