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 A047799 #11 Sep 08 2022 08:44:57 %S A047799 1,1,3,40,1015,40631,2334766,180836664,18067408311,2254675244287, %T A047799 342877692847261,62311687363814736,13318714515734069806, %U A047799 3304254169559017642774,940912768920331123369272,304601441677789509306775856 %N A047799 a(n) = Sum_{k=0..n} C(n,k)*Stirling1(n,k)^2. %H A047799 G. C. Greubel, <a href="/A047799/b047799.txt">Table of n, a(n) for n = 0..245</a> %p A047799 seq(add(binomial(n,k)*stirling1(n, k)^2, k = 0..n), n = 0..20); # _G. C. Greubel_, Aug 07 2019 %t A047799 Table[Sum[Binomial[n, k]*StirlingS1[n, k]^2, {k, 0, n}], {n,0,20}] (* _G. C. Greubel_, Aug 07 2019 *) %o A047799 (PARI) {a(n) = sum(k=0,n, binomial(n,k)*stirling(n,k,1)^2)}; %o A047799 vector(20, n, n--; a(n)) \\ _G. C. Greubel_, Aug 07 2019 %o A047799 (Magma) [(&+[Binomial(n,k)*StirlingFirst(n,k)^2: k in [0..n]]): n in [0..20]]; // _G. C. Greubel_, Aug 07 2019 %o A047799 (Sage) [sum(binomial(n,k)*stirling_number1(n,k)^2 for k in (0..n)) for n in (0..20)] # _G. C. Greubel_, Aug 07 2019 %o A047799 (GAP) List([0..20], n-> Sum([0..n], k-> Binomial(n,k)*Stirling1(n,k)^2 )) # _G. C. Greubel_, Aug 07 2019 %Y A047799 Cf. A008275, A047798, A122455. %K A047799 nonn %O A047799 0,3 %A A047799 _N. J. A. Sloane_