A330272 - OEIS

A330272

a(n) is the least nonnegative integer k such that n OR k is a cube (where OR denotes the bitwise OR operator).

0, 0, 25, 24, 121, 120, 337, 336, 0, 18, 17, 16, 113, 112, 3361, 3360, 11, 10, 9, 8, 105, 104, 321, 320, 3, 2, 1, 0, 97, 96, 29761, 29760, 93, 92, 1297, 1296, 89, 88, 3337, 3336, 85, 84, 3333, 3332, 81, 80, 3329, 3328, 77, 76, 1281, 1280, 73, 72, 59265, 59264

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OFFSET

0,3

COMMENTS

The sequence is well defined:

- for any k >= 0, the binary expansion of m = A000225(k)^3 has k trailing 1's,

- hence for any n < 2^k, n OR m = m, which is a cube, QED.

LINKS

Rémy Sigrist, Table of n, a(n) for n = 0..8192

Rémy Sigrist, PARI program for A330272

Rémy Sigrist, Scatterplot of (x, y) such that x OR y is a cube, 0 <= x, y <= 1023

FORMULA