A226902 Numbers c such that the difference of consecutive cubes (c+1)^3 - c^3 is the sum of two positive cubes.

5, 8, 18, 40, 53, 70, 102, 114, 188, 197, 213, 248, 255, 297, 306, 453, 460, 477, 487, 491, 495, 564, 632, 671, 684, 768, 909, 958, 989, 1190, 1290, 1324, 1331, 1346, 1744, 1745, 1779, 2068, 2130, 2178, 2208, 2262, 2448, 2790, 2813, 3320, 3327, 3402, 3414

Offset

1,1

Comments

The numbers c in A225909.

The sequence is infinite, because A226903 is a parametrized infinite subsequence.

Links

Chai Wah Wu, Table of n, a(n) for n = 1..5000

Formula

a(n) = (-3 + sqrt(9 + 12*(A225909(n) - 1)))/6

Example

(5+1)^3 - 5^3 = 3^3 + 4^3, so 5 is a member.

Crossrefs

Cf. A225909, A226903.

Sequence in context: A302393 A378971 A342804 * A347136 A326826 A026595

Adjacent sequences: A226899 A226900 A226901 * A226903 A226904 A226905

Keyword

nonn

Author

Jonathan Sondow, Jun 21 2013

Status

approved