A259836 -id:A259836 - cp's OEIS frontend

A272910 Numbers n such that (n-1)^3 + (n+1)^3 is a taxi-cab number (A001235).

19, 32, 93, 124, 208, 243, 308, 395, 427, 471, 603, 672, 1057, 1568, 1892, 2181, 2223, 2587, 3040, 3049, 4037, 4336, 5232, 5556, 6196, 6305, 6643, 8288, 8748, 10161, 10185, 10612, 10985, 12352, 13741, 14807, 16021, 17568, 20352, 20653, 24080, 27216, 27867, 31113, 31869, 32032, 32500, 36593

Offset: 1

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Altug Alkan, May 09 2016

nonn

Numbers n such that 2*n*(n^2+3) is a member of A001235.
19 and 3049 are the only prime numbers in this sequence for n < 10^5.
How is the graph of second differences of this sequence?

			19 is a term because 18^3 + 20^3 = 13832 = 2^3 + 24^3.

Chai Wah Wu, Table of n, a(n) for n = 1..300

Cf. A001235, A153976, A259836.

T = thueinit(x^3+1, 1);
isA001235(n) = my(v=thue(T, n)); sum(i=1, #v, v[i][1]>=0 && v[i][2]>=v[i][1])>1;
lista(nn) = for(n=1, nn, if(isA001235(2*n*(n^2+3)), print1(n, ", ")));

cp's OEIS Frontend

A272910 Numbers n such that (n-1)^3 + (n+1)^3 is a taxi-cab number (A001235).

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