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 A226123 Number of terms of the form 2^k in Collatz(3x+1) trajectory of n. 2
 1, 2, 5, 3, 5, 5, 5, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 7, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 5, 5, 5, 5, 5, 5, 5, 5, 5, 7, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 7, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 9, 5, 5, 5, 5, 5, 5, 5, 5, 7, 9, 5, 5 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(n) = sum(A209229(A070165(n,k)): k=1..A006577(n)). - Reinhard Zumkeller, May 30 2013 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 EXAMPLE a(3)=5 since Collatz trajectory of 3 contains terms 1,2,4,8 and 16. MATHEMATICA coll[n_]:=NestWhileList[If[EvenQ[#], #/2, 3#+1]&, n, #>1&]; Table[Length[Select[coll[n], IntegerQ[Log[2, #]]&]], {n, 87}] PROG (Haskell) a226123 = sum . map a209229 . a070165_row -- Reinhard Zumkeller, May 30 2013 CROSSREFS Cf. A070165. Cf. A135282, A208981. Sequence in context: A266407 A249273 A078376 * A216052 A021911 A248852 Adjacent sequences:  A226120 A226121 A226122 * A226124 A226125 A226126 KEYWORD nonn AUTHOR Jayanta Basu, May 27 2013 STATUS approved

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Last modified May 10 03:51 EDT 2021. Contains 343748 sequences. (Running on oeis4.)