A257489 Arrange numbers in a single clockwise spiral so that each number is relatively prime to its 12 nearest neighbors.

1, 2, 3, 5, 4, 7, 9, 11, 13, 15, 17, 19, 8, 23, 29, 27, 25, 31, 37, 10, 41, 43, 14, 47, 53, 16, 49, 59, 55, 21, 61, 65, 67, 22, 71, 73, 6, 77, 79, 39, 83, 89, 12, 91, 85, 57, 97, 101, 33, 35, 103, 107, 18, 109, 113, 32, 45, 121, 119, 81, 95, 127, 131, 115, 133

Offset: 1

Author

Jon E. Schoenfield, Apr 26 2015

Keywords

• nonn

Comments

In the illustration of initial terms (see Links), the 12 nearest neighbors of the first term are highlighted in yellow.

Links

• Jon E. Schoenfield, Table of n, a(n) for n = 1..50000
• Jon E. Schoenfield, Illustration of initial terms
• Jon E. Schoenfield, Graph of first 50000 terms

Crossrefs

Cf. A064413, A257321-A257340.