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 A006260 M5162 #31 Jul 01 2025 21:40:25 %S A006260 0,24,444,4400,32120,195800,1062500,5326160,25243904,114876376, %T A006260 507259276,2189829808,9292526920,38917528600,161343812980, %U A006260 663661077072,2713224461136,11039636532120,44751359547420,180880752056880 %N A006260 Second-order Eulerian numbers <<n,3>>. %D A006260 R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics, 2nd edition. Addison-Wesley, Reading, MA, 1994, p. 270. %D A006260 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A006260 Seiichi Manyama, <a href="/A006260/b006260.txt">Table of n, a(n) for n = 3..1000</a> %H A006260 I. Gessel and R. P. Stanley, <a href="https://doi.org/10.1016/0097-3165(78)90042-0">Stirling polynomials</a>, J. Combin. Theory, A 24 (1978), 24-33. %F A006260 G.f.: x^4(24-36x-280x^2+652x^3-168x^4-288x^5)/((1-x)^4(1-2x)^3(1-3x)^2(1-4x)). - _Michael Somos_, Oct 13 2002 %F A006260 a(n) = sum((-1)^(n+k+2)*binomial(2*n+1,k)*stirling1(2*n-k-3,n-k-3), k=0..n-4). [_Johannes W. Meijer_, Oct 16 2009]. %p A006260 G:=x^4*(24-36*x-280*x^2+652*x^3-168*x^4-288*x^5)/((1-x)^4*(1-2*x)^3*(1-3*x)^2*(1-4*x)): Gser:=series(G,x=0,27): seq(coeff(Gser,x^n),n=3..25); %Y A006260 a(n) = A008517(n, 4). %Y A006260 3rd column of A201637. %Y A006260 Equals for n=>4 fifth right hand column of A163936. [_Johannes W. Meijer_, Oct 16 2009]. %K A006260 nonn,easy %O A006260 3,2 %A A006260 _N. J. A. Sloane_, _Mira Bernstein_, _Robert G. Wilson v_ %E A006260 More terms from _Emeric Deutsch_, Dec 15 2004