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 A276977 #15 May 16 2023 11:29:19
%S A276977 1,1,11,315,17129,1510425,196385475,35327367075,8399994587985,
%T A276977 2550903574364145,963207568455370875,442613044315692124875,
%U A276977 243195136160954426677305,157442856285298191126143625,118607799383105394973766029875,102867257381973743111023517821875
%N A276977 Duplicate of A106827.
%H A276977 Vincenzo Librandi, <a href="/A276977/b276977.txt">Table of n, a(n) for n = 0..200</a>
%F A276977 a(n) = (-1)^n * Sum_{k=0..n} Stirling1(n+k, k) * !(n-k) * C(2*n, n+k), where !n = A000166(n) is the subfactorial, C(n,k) are binomial coefficients.
%t A276977 Table[(-1)^n Sum[StirlingS1[n+k, k] Subfactorial[n-k] Binomial[2n, n+k], {k, 0, n}], {n, 0, 20}]
%Y A276977 Cf. A055505, A055535, A000166.
%K A276977 dead
%O A276977 0,3
%A A276977 _Vladimir Reshetnikov_, Sep 23 2016