A103299 Number of optimal rulers with n segments (n>=0).

1, 1, 2, 2, 4, 6, 12, 4, 6, 2, 2, 4, 12, 4, 2, 2, 2, 2, 4, 2, 2, 2, 2, 2, 4

Offset: 0

Author

Peter Luschny, Feb 28 2005

Keywords

• nonn
• hard
• more

Comments

For definitions, references and links related to complete rulers see A103294.

Examples

			a(5)=6 counts the optimal rulers with 5 segments, {[0,1,6,9,11,13], [0,2,4,7,12,13], [0,1,4,5,11,13], [0,2,8,9,12,13], [0,1,2,6,10,13], [0,3,7,11,12,13]}.
		

Links

• F. Schwartau, Y. Schröder, L. Wolf and J. Schoebel, MRLA search results and source code, Nov 6 2020.
• F. Schwartau, Y. Schröder, L. Wolf and J. Schoebel, Large Minimum Redundancy Linear Arrays: Systematic Search of Perfect and Optimal Rulers Exploiting Parallel Processing, IEEE Open Journal of Antennas and Propagation, 2 (2021), 79-85.
• Index entries for sequences related to perfect rulers.

Crossrefs

Cf. A103296 (Complete rulers with n segments), A103301 (Perfect rulers with n segments).

Formula

a(n) = A103300(A004137(n+1)).

Extensions

Terms a(20)-a(24) proved by exhaustive search by Fabian Schwartau, Yannic Schröder, Lars Wolf, Joerg Schoebel, Feb 22 2021