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

Author

Jonathan Sondow, Jun 21 2013

Keywords

• nonn

Comments

The numbers c in A225909.

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

Examples

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

Links

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

Crossrefs

Cf. A225909, A226903.

Formula

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