This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A280945 List of primitive triples (x, y, z) of positive integers for which xy - z, yz - x, and zx - y are powers of 2. 0
 2, 2, 2, 2, 2, 3, 2, 6, 11, 3, 5, 7 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS There are sixteen such triples, namely (2, 2, 2), the three permutations of (2, 2, 3), and the six permutations of each of (2, 6, 11) and (3, 5, 7). See the proof in the link. The sixteen triples are (2, 2, 2), (2, 2, 3), (2, 3, 2), (3, 2, 2), (2, 6, 11), (2, 11, 6), (6, 2, 11), (6, 11, 2), (11, 2, 6), (11, 6, 2), (3, 5, 7), (3, 7, 5), (5, 3, 7), (5, 7, 3), (7, 3, 5) and (7, 5, 3). LINKS 56th International Mathematical Olympiad, Problem N5 EXAMPLE The 3th primitive triple (x, y, z) = (2, 6, 11) is in the sequence because xy - z = 1, yz - x = 2^6 and zx - y = 2^4. CROSSREFS Sequence in context: A165054 A067743 A029230 * A196067 A251141 A319696 Adjacent sequences:  A280942 A280943 A280944 * A280946 A280947 A280948 KEYWORD nonn,fini,full,tabf AUTHOR Michel Lagneau, Jan 11 2017 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
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 15 09:05 EST 2019. Contains 329995 sequences. (Running on oeis4.)