A226123 Number of terms of the form 2^k in Collatz(3x+1) trajectory of n.

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

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 * A368658 A216052 A021911

Adjacent sequences: A226120 A226121 A226122 * A226124 A226125 A226126

Keyword

nonn

Author

Jayanta Basu, May 27 2013

Status

approved