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# The Number of the Day: 741

Pink Floyd’s Dark Side of the Moon spent 741 weeks—more than 14 years—on the Billboard Top 200 album chart.

Related Fact: Syd Barrett got the name Pink Floyd from two American blues musicians, Pink Anderson and Floyd Council.

[Source: Stacy Conradt's Quick 10 on Billboard Milestones. See previous Numbers of the Day here.]

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This Puzzling Math Brain Teaser Has a Simple Solution
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Fans of number-based brainteasers might find themselves pleasantly stumped by the following question, posed by TED-Ed’s Alex Gendler: Which sequence of integers comes next?

1, 11, 21, 1211, 111221, ?

Mathematicians may recognize this pattern as a specific type of number sequence—called a “look-and-say sequence"—that yields a distinct pattern. As for those who aren't number enthusiasts, they should try reading the numbers they see aloud (so that 1 becomes "one one," 11 is "two ones," 21 is "one two, one one,” and so on) to figure the answer.

Still can’t crack the code? Learn the surprisingly simple secret to solving the sequence by watching the video below.

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