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A075257
Smaller terms in the pairs of numbers (a < b) in the sequence {a,b}-> {Max[{a,b}]-Min[{a,b}],k*Min[{a,b}]} with k=3 and the first pair {a=1,b=2}. See A075256.
3
1, 1, 2, 1, 3, 2, 6, 1, 3, 9, 5, 15, 7, 21, 17, 46, 5, 15, 45, 73, 62, 157, 29, 87, 261, 94, 282, 407, 439, 782, 535, 1605, 206, 618, 1854, 2137, 3425, 2986, 7289, 1669, 5007, 15021, 170, 510, 1530, 4590, 13770, 24493, 16817, 50451, 6211, 18633, 55899
OFFSET
1,3
COMMENTS
Take any pair {a,b}. Each next pair is get by the rule {a,b} -> Sort[{Max[{a,b}]-Min[{a,b}],k*Min[{a,b}]]. Here k=3 and the first {a,b}={1,2}. For k = 2 there is a fixed point {a,b=2a}. For k > 2, are there any limits or cycles of the sequence {for some initial pair {a,b}?
LINKS
FORMULA
a(n) = A075256(2*n-1).
MATHEMATICA
ss=Table[0, {j, 100}]; s=ss[[1]]={1, 2}; Do[ss[[i]]=Sort[{Max[s]-Min[s], 3*Min[s]}]; s=ss[[i]], {i, 2, 100}]; Table[Flatten[ss][[i]], {i, 1, 199, 2}]
PROG
(PARI) my(x=1, y=2); print1(x, ", "); for(n=2, 53, my(mx=max(x, y), mi=min(x, y)); x=min(mx-mi, 3*mi); y=max(mx-mi, 3*mi); print1(x, ", ")) \\ Hugo Pfoertner, Mar 21 2020
CROSSREFS
Sequence in context: A266138 A014000 A339612 * A260618 A306286 A226651
KEYWORD
nonn
AUTHOR
Zak Seidov, Sep 10 2002
STATUS
approved