A375889 a(1) = 1, a(2) = 3; for n > 2, a(n) is the smallest unused positive number such that a(n) shares a factor with a(n-1) and (a(n) AND a(n-1)) = min(a(n), a(n-1)), where AND is the binary AND operation.
1, 3, 15, 5, 45, 9, 27, 18, 2, 6, 4, 12, 8, 10, 14, 30, 16, 20, 22, 54, 32, 34, 38, 36, 39, 33, 51, 17, 85, 65, 75, 66, 64, 68, 70, 78, 72, 74, 90, 24, 26, 58, 40, 42, 46, 44, 60, 28, 62, 48, 50, 55, 35, 63, 7, 119, 21, 87, 69, 93, 81, 117, 52, 116, 80, 82, 86, 84, 92, 76, 94, 88, 120, 56, 122, 96
Offset: 1
Keywords
Examples
a(4) = 5 as 5 shares a factor with a(3) = 15 and min(15,5) = 5 and (5 AND 15) = 101_2 AND 1111_2 = 101_2 = 5.
Links
- Scott R. Shannon, Table of n, a(n) for n = 1..10000
Comments