perplexus.info :: Sequences : Shapes are too Deep

Shapes are too Deep (Posted on 2005-06-01)

What are the next three numbers:

1, 2, 4, 7, 13, 23, 39, 64, 99, 150, 216, __, __, __?

Submitted by Dustin

Rating: 3.6000 (5 votes)

Solution: (Hide)

307, 419, and 567.

If you take the second difference of the sequence, you get:
1, 1, 3, 4, 6, 9, 10, 16, 15, __, __, __.
Every other number is a triangular number, and every other is a square number. The next three in the second difference are 25, 21, 36.

Comments: ( You must be logged in to post comments.)

Subject	Author	Date
Puzzle Solution	K Sengupta	2008-12-01 15:16:35
Answer	K Sengupta	2008-10-24 05:53:20
explanation	armando	2005-06-07 14:41:51
I agree	armando	2005-06-02 18:59:06
Possible solutions	Colby	2005-06-01 19:31:46

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