login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A103301 Number of perfect rulers with n segments (n>=0). 4

%I #13 Feb 23 2021 18:20:55

%S 1,1,3,9,24,88,254,1064,1644,3382,4156,8022,26264,52012,25434,8506,

%T 5632,6224,12330,34224,108854,103156,75992,86560,69084

%N Number of perfect rulers with n segments (n>=0).

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

%H F. Schwartau, Y. Schröder, L. Wolf and J. Schoebel, <a href="https://dx.doi.org/10.21227/cd4b-nb07">MRLA search results and source code</a>, Nov 6 2020.

%H F. Schwartau, Y. Schröder, L. Wolf and J. Schoebel, <a href="https://doi.org/10.1109/OJAP.2020.3043541">Large Minimum Redundancy Linear Arrays: Systematic Search of Perfect and Optimal Rulers Exploiting Parallel Processing</a>, IEEE Open Journal of Antennas and Propagation, 2 (2021), 79-85.

%H <a href="/index/Per#perul">Index entries for sequences related to perfect rulers.</a>

%F a(n) = Sum_{i=A004137(n)+1..A004137(n+1)} A103300(i), n>=1.

%e a(3)=9 counts the perfect rulers with 3 segments, {[0,1,2,4],[0,2,3,4], [0,1,3,4],[0,1,3,5],[0,2,4,5],[0,1,2,5],[0,3,4,5],[0,1,4,6],[0,2,5,6]}.

%Y Cf. A103300, A103297, A103296 (Complete rulers with n segments), A103299 (Optimal rulers with n segments).

%K nonn,hard

%O 0,3

%A _Peter Luschny_, Feb 28 2005

%E Terms a(19)-a(24) found by exhaustive search by Fabian Schwartau, _Yannic Schröder_, Lars Wolf, Joerg Schoebel, Feb 23 2021

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 29 08:08 EDT 2024. Contains 371265 sequences. (Running on oeis4.)