A217735 a(n) = the least positive integer m such that n^3 + m^3 is a square, or 0, if (presumably) there is no such m.

2, 1, 0, 8, 0, 0, 21, 4, 18, 65, 37, 0, 0, 70, 0, 32, 0, 9, 0, 0, 7, 26, 1177, 0, 50, 22, 0, 84, 0, 0, 0, 16, 88, 450, 665, 72, 11, 1178, 0, 260, 0, 0, 0, 148, 0, 2, 0, 0, 98, 25, 0, 0, 0, 0, 0, 65, 112, 0, 0, 0, 0, 0, 189, 128, 10, 0, 0, 0, 0, 14, 0, 36, 0, 0, 0, 0, 0, 273, 0, 0, 162, 0, 0, 28, 0, 602, 0, 33, 0, 585, 65, 4708, 0, 0, 1121

Offset

1,1

Comments

All zero terms are suggestive(?). All positive terms are certain.

Links

Giovanni Resta, Table of n, a(n) for n = 1..1000 (see comments in b-file)

Example

n=1: 1^3+2^3=3^2
n=2: 2^3+1^3=3^2
n=4: 4^3+8^3=24^2
n=7: 7^3+21^3=98^2

Crossrefs

Cf. A103254 (values of n such that a(n) > 0).

Sequence in context: A325872 A021896 A188835 * A369585 A075615 A195284

Adjacent sequences: A217732 A217733 A217734 * A217736 A217737 A217738

Keyword

nonn

Author

Zak Seidov, Mar 22 2013

Status

approved