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 A309839 #17 Sep 24 2019 21:42:05 %S A309839 3,6,7,12,15,22,23,42,43,48,63,76,79,96,115,140,143,166,167,192,247, %T A309839 248,279,312,347,384,423,472,483,526,527,572,619,624,719,724,827,832, %U A309839 889,948,1009,1072,1087,1152,1219,1288,1359,1432,1507,1520,1597,1676,1679 %N A309839 a(n) = GAP_n: first integer m that is not the dimension of a semisimple subalgebra of M_n(k). %C A309839 Define the sequence a(n) = GAP_n to be the smallest integer that is not the dimension of a semisimple subalgebra of M_n(k). This is one more than the upper endpoint of the continuous region of M_n(k). Because when n = 1 there are no gaps, this sequence begins at n = 2. See Heikoop paper, page 31. %H A309839 Michael De Vlieger, <a href="/A309839/b309839.txt">Table of n, a(n) for n = 2..101</a> %H A309839 Phillip Tomas Heikoop, <a href="https://digitalcommons.wpi.edu/mqp-all/6822">Dimensions of Matrix Subalgebras</a>, Bachelor's Thesis, Worcester Polytechnic Institute (2019). %H A309839 Phillip Heikoop, <a href="/A309839/a309839.cpp.txt">C++11 code to generate the sequence</a> %F A309839 a(n) > n^2 - 4 * sqrt(n + 2). %Y A309839 Cf. A000124, A002620, A069999, A138544, A309838. %K A309839 nonn %O A309839 2,1 %A A309839 _Phillip Heikoop_, Aug 19 2019