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Centered cube numbers that can be written as sums of two other cubes in at least two ways.
16

%I #19 Mar 13 2022 18:44:14

%S 3587409,8741691,26122131,355957875,2593625571,2746367559,70607389041,

%T 367954598375,7006302268875,7916366521691,8091803325879,

%U 28332679374909,144757538551899,1026401875608375,9339629571431315,14295468330521189,49873257556492139,42892025638971003759

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

%C 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).

%C Subsequence of A005898 and of A352133.

%H A. Grinstein, <a href="https://web.archive.org/web/20040320144821/http://zadok.org/mattandloraine/1729.html">Ramanujan and 1729</a>, University of Melbourne Dept. of Math and Statistics Newsletter: Issue 3, 1998.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/CenteredCubeNumber.html">Centered Cube Number</a>

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

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

%Y Cf. A005898, A001235, A272885, A352133, A352134, A352135, A352136, A352221, A352222, A352223, A352224, A352225.

%K nonn

%O 1,1

%A _Vladimir Pletser_, Mar 07 2022

%E a(6)-a(18) from _Jon E. Schoenfield_, Mar 09 2022