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 A192458 #11 Feb 05 2016 06:48:31 %S A192458 0,1,7,59,605,7365,104055,1675275,30290085,607828725,13406691375, %T A192458 322415322075,8396547684525,235419569309925,7070492932878375, %U A192458 226469231898784875,7706144167912315125,277613088828805855125,10555630035365385345375 %N A192458 a(n) = A192457(n)/2. %C A192458 See A192457. %F A192458 a(n) = (1/3)*(2^n(n+1)! - (2n-1)!!). - _Vaclav Potocek_, Feb 04 2016 %e A192458 (See A192457.) %t A192458 (See A192457.) %Y A192458 Cf. A192457. %K A192458 nonn %O A192458 0,3 %A A192458 _Clark Kimberling_, Jul 01 2011