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A352220

Centered cube numbers that can be written as sums of two other cubes in at least two ways.

3587409, 8741691, 26122131, 355957875, 2593625571, 2746367559, 70607389041, 367954598375, 7006302268875, 7916366521691, 8091803325879, 28332679374909, 144757538551899, 1026401875608375, 9339629571431315, 14295468330521189, 49873257556492139, 42892025638971003759

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OFFSET

1,1

COMMENTS

Numbers A such that A = B^3 + (B+1)^3 = C^3 + D^3 = E^3 + F^3 with C <> (D +- 1), E <> (F +- 1), E > C > B, C > |D| and E > |F|, where A = a(n) (this sequence), B = A352221(n), C = A352222(n), D = A352223(n), E = A352224(n) and F = A352225(n).

Subsequence of A005898 and of A352133.

LINKS

Table of n, a(n) for n=1..18.

A. Grinstein, Ramanujan and 1729, University of Melbourne Dept. of Math and Statistics Newsletter: Issue 3, 1998.

Eric Weisstein's World of Mathematics, Centered Cube Number

FORMULA

a(n) = A352221(n)^3 + (A352221(n) + 1)^3 = A352222(n)^3 + A352223(n)^3 = A352224(n)^3 + A352225(n)^3.

EXAMPLE

3587409 belongs to the sequence because 3587409 = 121^3 + 122^3 = 153^3 + 18^3 = 369^3 + (-360)^3.

CROSSREFS