OFFSET
1,2
COMMENTS
Size of intersection of row n and row n+1 in A070165.
LINKS
EXAMPLE
. | Rows in A070165 (trajectories)
a(1) = #{1} = 1; | 1
a(2) = #{2,1} = 2; | 2,1
a(3) = #{4,2,1} = 3; | 3,10,5,16,8,4,2,1
a(4) = #{4,2,1} = 3; | 4,2,1
a(5) = #{5,16,8,4,2,1} = 6; | 5,16,8,4,2,1
a(6) = #{10,5,16,8,4,2,1} = 7; | 6,3,10,5,16,8,4,2,1
a(7) = #{8,4,2,1} = 4; | 7,22,11,34,17,52,26,13,40,20,10,5,..
a(8) = #{8,4,2,1} = 4; | 8,4,2,1
a(9) = #{10,5,16,8,4,2,1} = 7; | 9,28,14,7,22,11,34,17,52,26,13,40,..
a(10) = #{10,5,16,8,4,2,1} = 7; | 10,5,16,8,4,2,1
a(11) = #{10,5,16,8,4,2,1} = 7; | 11,34,17,52,26,13,40,20,10,5,16,8,4,..
a(12) = #{10,5,16,8,4,2,1} = 7. | 12,6,3,10,5,16,8,4,2,1
. | 13,40,20,10,5,16,8,4,2,1 .
MATHEMATICA
coll[n_]:=NestWhileList[If[EvenQ[#], #/2, 3#+1]&, n, #>1&]; Table[Length[Intersection[coll[n], coll[n+1]]], {n, 76}] (* Jayanta Basu, May 28 2013 *)
PROG
(Haskell)
import Data.List (intersect)
a187763 n = a187763_list !! (n-1)
a187763_list = map length $
zipWith intersect a070165_tabf $ tail a070165_tabf
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Jan 04 2013
STATUS
approved