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A213909 Sum of all even numbers in Collatz (3x+1) trajectory of n. 8
0, 2, 40, 6, 30, 46, 234, 14, 276, 40, 212, 58, 100, 248, 562, 30, 178, 294, 424, 60, 126, 234, 516, 82, 538, 126, 81178, 276, 366, 592, 80910, 62, 688, 212, 446, 330, 444, 462, 1894, 100, 81096, 168, 1090, 278, 416, 562, 80816, 130, 666, 588, 926, 178, 340 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

T. D. Noe, Table of n, a(n) for n = 1..10000

EXAMPLE

a(5)=30 since Collatz trajectory of 5 is 5,16,8,4,2,1.

MATHEMATICA

Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; Table[Total[Select[Collatz[n], EvenQ]], {n, 100}] (* T. D. Noe, Mar 05 2013 *)

CROSSREFS

Cf. A033493.

Sequence in context: A247878 A232086 A047660 * A073418 A275547 A269544

Adjacent sequences:  A213906 A213907 A213908 * A213910 A213911 A213912

KEYWORD

nonn

AUTHOR

Jayanta Basu, Mar 05 2013

STATUS

approved

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Last modified October 13 16:50 EDT 2019. Contains 327968 sequences. (Running on oeis4.)