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 A047792 #11 Sep 08 2022 08:44:57
%S A047792 1,1,0,-6,36,50,-6575,145222,-1489978,-49083480,4200404478,
%T A047792 -182031111702,4165517606173,176264238017452,-33427749628678925,
%U A047792 2913726991238703330,-165770248921085801710,1422295225609567363172,1326793746164926878993976
%N A047792 a(n) = Sum_{k=0..n} Stirling1(n,k)*Stirling2(n,k).
%H A047792 G. C. Greubel, <a href="/A047792/b047792.txt">Table of n, a(n) for n = 0..295</a>
%p A047792 seq(add(stirling1(n, k)*stirling2(n, k), k = 0..n), n = 0..20); # _G. C. Greubel_, Aug 07 2019
%t A047792 Flatten[{1, Table[Sum[StirlingS1[n, k]*StirlingS2[n, k], {k, n}], {n,20}] }] (* _Vaclav Kotesovec_, Oct 13 2018 *)
%o A047792 (PARI) {a(n) = sum(k=0,n, stirling(n,k,1)*stirling(n,k,2))};
%o A047792 vector(20, n, n--; a(n)) \\ _G. C. Greubel_, Aug 07 2019
%o A047792 (Magma) [(&+[StirlingFirst(n,k)*StirlingSecond(n,k): k in [0..n]]): n in [0..20]]; // _G. C. Greubel_, Aug 07 2019
%o A047792 (Sage) [sum((-1)^(n-k)*stirling_number1(n,k)*stirling_number2(n,k) for k in (0..n)) for n in (0..20)] # _G. C. Greubel_, Aug 07 2019
%o A047792 (GAP) List([0..20], n-> Sum([0..n], k-> (-1)^(n-k)*Stirling1(n,k) *Stirling2(n,k) )); # _G. C. Greubel_, Aug 07 2019
%Y A047792 Cf. A008275, A008277, A047793, A047794, A047795.
%K A047792 sign
%O A047792 0,4
%A A047792 _N. J. A. Sloane_