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 A088214 #3 Mar 31 2012 10:29:03 %S A088214 324,329,355,357,358,362,364,365,367,373,375,378,381,383,386,387,394, %T A088214 397,399,401,403,406,409,411 %N A088214 Numbers less than the maximum possible determinant A085000(3)=412 not occurring as determinant of a 3 X 3 matrix with elements 1..9. %H A088214 Hugo Pfoertner, <a href="http://www.randomwalk.de/sequences/a088215.pdf">Possible determinants of 3 X 3 matrix with elements 1..9.</a> %e A088214 398 is not in the sequence because it can be expressed as det ((9 3 5)(4 8 2)(1 6 7)). %Y A088214 Cf. A085000, A088215, A088216, A088217. %K A088214 fini,full,nonn %O A088214 1,1 %A A088214 _Hugo Pfoertner_, Sep 23 2003