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A080816
Triangle read by rows in which n-th row gives trajectory of n (omitting n itself) under the map k -> k+1 if k odd, k -> k/2 if k even.
1
1, 4, 2, 1, 2, 1, 6, 3, 4, 2, 1, 3, 4, 2, 1, 8, 4, 2, 1, 4, 2, 1, 10, 5, 6, 3, 4, 2, 1, 5, 6, 3, 4, 2, 1, 12, 6, 3, 4, 2, 1, 6, 3, 4, 2, 1, 14, 7, 8, 4, 2, 1, 7, 8, 4, 2, 1, 16, 8, 4, 2, 1, 8, 4, 2, 1, 18, 9, 10, 5, 6, 3, 4, 2, 1, 9, 10, 5, 6, 3, 4, 2, 1, 20, 10, 5, 6, 3, 4, 2, 1, 10, 5, 6, 3, 4, 2, 1, 22
OFFSET
1,2
EXAMPLE
7 -> 8 -> 4 -> 2 -> 1, so the 7th row is 8,4,2,1.
MATHEMATICA
Table[Rest[NestWhileList[If[OddQ[#], #+1, #/2]&, n, #>1&]], {n, 30}] //Flatten (* Harvey P. Dale, Dec 04 2016 *)
PROG
(PARI) xnp1(n, p) = { print1(1" "); for(x=1, n, p1 = x; while(p1>1, if(p1%2==0, p1/=2, p1 = p1*p+1; ); print1(p1" ") ) ) }
CROSSREFS
Sequence in context: A348136 A235795 A046096 * A016507 A270047 A132116
KEYWORD
easy,nonn,tabf
AUTHOR
Cino Hilliard, Mar 26 2003
STATUS
approved