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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.)