A352133 - OEIS

%I #20 Mar 14 2022 17:54:35

%S 91,189,1729,12691,68705,97309,201159,400491,2484755,2554741,3587409,

%T 3767491,8741691,15407765,26122131,54814509,121861441,139361059,

%U 168632191,223264809,236019771,295233841,355957875,448404255,508476241,525518721,1041378589,2593625571,2746367559,2874318841,4328420941,5193550999

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

%C Numbers that are the sum of two consecutive cubes and at least one other sum of two cubes: a(n) = b(n)^3 + (b(n) + 1)^3 = c(n)^3 + d(n)^3, with c(n) > b(n) and c(n) > |d(n)|, and where b(n)=A352134(n), c(n)=A352135(n) and d(n)=A352136(n).

%C Subsequence of A005898.

%H Vladimir Pletser, <a href="/A352133/b352133.txt">Table of n, a(n) for n = 1..275</a>

%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="https://mathworld.wolfram.com/CenteredCubeNumber.html">Centered Cube Number</a>

%F a(n) = A352134(n)^3 + (A352134(n) + 1)^3 = A352135(n)^3 + A352136(n)^3.

%e 91 belongs to the sequence because 91 = 3^3 + 4^3 = 6^3 + (-5)^3.

%Y Cf. A005898, A001235, A272885, A352134, A352135, A352136, A352220, A352221, A352222, A352223, A352224, A352225.

%K nonn

%O 1,1

%A _Vladimir Pletser_, Mar 05 2022