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 Little cubes (Posted on 2010-02-27)
The difference of the cubes of two non-negative successive integers is a square of an integer. Find few possible pairs.
How about a general formula or evaluation algorithm for a(n)?

 Submitted by Ady TZIDON Rating: 4.0000 (2 votes) Solution: (Hide) Some couples (a,b) for (a+1)^3-a^3=b^2 : (0, 1), (7, 13), (104, 181),... To get more, use the recurrence relations : a[n] = 14a[n-1] - a[n-2] + 6 and b[n] = 14b[n-1] - b[n-2]

 Subject Author Date re: computer exploration -- Sloane back on-line Charlie 2010-03-01 03:02:49 Analytical findings (spoiler) Harry 2010-02-27 21:14:12 re(2): computer exploration Brian Smith 2010-02-27 18:51:49 re: computer exploration Jim Keneipp 2010-02-27 18:20:40 computer exploration Charlie 2010-02-27 14:29:40

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