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A352220 Centered cube numbers that can be written as sums of two other cubes in at least two ways.

%I A352220 #20 Feb 16 2025 08:34:03
%S A352220 3587409,8741691,26122131,355957875,2593625571,2746367559,70607389041,
%T A352220 367954598375,7006302268875,7916366521691,8091803325879,
%U A352220 28332679374909,144757538551899,1026401875608375,9339629571431315,14295468330521189,49873257556492139,42892025638971003759
%N A352220 Centered cube numbers that can be written as sums of two other cubes in at least two ways.
%C A352220 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 A352220 Subsequence of A005898 and of A352133.
%H A352220 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 A352220 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/CenteredCubeNumber.html">Centered Cube Number</a>
%F A352220 a(n) = A352221(n)^3 + (A352221(n) + 1)^3 = A352222(n)^3 + A352223(n)^3 = A352224(n)^3 + A352225(n)^3.
%e A352220 3587409 belongs to the sequence because 3587409 = 121^3 + 122^3 = 153^3 + 18^3 = 369^3 + (-360)^3.
%Y A352220 Cf. A005898, A001235, A272885, A352133, A352134, A352135, A352136, A352221, A352222, A352223, A352224, A352225.
%K A352220 nonn
%O A352220 1,1
%A A352220 _Vladimir Pletser_, Mar 07 2022
%E A352220 a(6)-a(18) from _Jon E. Schoenfield_, Mar 09 2022