What is the next number? 1,2,8,48,384,?

12 Answers

  • It’s 3840. The pattern is

    multiply by 2 then 4 then 6 then 8 then 10, … .

  • 1

    1×2 = 2

    2×4 = 8

    8×6 = 48

    48×8 = 384

    384×10 = 3840

    12×3480 = 41760

    This can be written as either of the following:

    (2n)!!

    (2^n) n!

    Note that !! does not mean to do factorial twice. The ! means factorial. !! means something called "double factorial."

    So for n=5 (what you want), put:

    (2^5) 5!

    = 32 × (5 × 4 × 3 × 2 × 1)

    = 32 × 120 = 3480

    Double factorial is where you take every other one. For n=5, we can do:

    (2×5)!! = 10!!

    = 10 × 8 × 6 × 4 × 2

    notice we take every other factor as we count down from 10

    = 3480

    Which also demonstrates how this recursion actually defines the !! function.

    Source(s): See also: http://en.wikipedia.org/wiki/Double_factorial#Doub…
  • 2 x 1 = 2

    4 x 2 = 8

    6 x 8 = 48

    8 x 48 = 348

    10 x 348 = 3480

    12 x 3480 = 41,760

  • 3840

    1*2 = 2

    2 *4 = 8

    8 * 6 = 48

    48 * 8 = 384

    384 * 10 = 3840

    thus multiply it times 10 to get 3840

  • 1 2 8 48 384

  • Appears to be successive multiples of 2, so 10 x 384 = 3840

  • 3840…each subsequent number is being multipied by the next number counted by two.

    1 (x2) 2 (x4) 8 (x6) 48 (x8) 384 (x10) 3840.

  • 3840

    You are multiplying each term by,then 4, then 6, then 8 then 10, then 12, etc

  • 3840 followed by 46080

    in statistics this is called (perfect) autocorrelation

    try a harder one

  • the sequence is like this!

    1×2=2

    2×4=8

    8×6=48

    48×8=384

    so..

    384×10=3840

    hope this helped!

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