This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A103297 #12 Feb 24 2021 08:15:32 %S A103297 1,1,2,3,3,4,4,6,6,7,7,7,8,10,11,11,11,11,11,13,14,15,15,16,14,19 %N A103297 Number of different lengths that perfect rulers with n segments can have. %C A103297 For definitions, references and links related to complete rulers see A103294. %H A103297 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 A103297 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 A103297 <a href="/index/Per#perul">Index entries for sequences related to perfect rulers.</a> %F A103297 a(n) = A004137(n+1) - A004137(n) for n>= 1. %e A103297 a(5)=4 because a perfect ruler with 5 segments may have the length 10, 11, 12 or 13. %Y A103297 Cf. A103298. %K A103297 nonn,hard %O A103297 0,3 %A A103297 _Peter Luschny_, Feb 28 2005 %E A103297 Term a(19) corrected and terms a(20)-a(25) added by Fabian Schwartau, _Yannic Schröder_, Lars Wolf, Joerg Schoebel, Feb 23 2021