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 A196795 #13 Jan 20 2017 18:31:39
%S A196795 1,4,22,145,1096,9259,85924,865183,9364864,108173827,1325589676,
%T A196795 17149360111,233271228880,3324545097475,49493784653644,
%U A196795 767665750130839,12376226335249024,206967901014192643,3583561993192959436,64136093489935863583,1184711492540805987856
%N A196795 a(n) = Sum_{k=0..n} binomial(n,k)*3^k*(k+1)^(n-k).
%F A196795 O.g.f.: Sum_{n>=0} 3^n*x^n/(1 - (n+1)*x)^(n+1).
%F A196795 E.g.f.: exp(x + 3*x*exp(x)).
%t A196795 Table[Sum[Binomial[n,k]3^k (k+1)^(n-k),{k,0,n}],{n,0,20}] (* _Harvey P. Dale_, Nov 12 2012 *)
%o A196795 (PARI) {a(n)=sum(k=0,n,binomial(n,k)*3^k*(k+1)^(n-k))}
%o A196795 (PARI) {a(n)=polcoeff(sum(m=0,n,3^m*x^m/(1-(m+1)*x+x*O(x^n))^(m+1)),n)}
%o A196795 (PARI) {a(n)=n!*polcoeff(exp(x+3*x*exp(x+x*O(x^n))),n)}
%Y A196795 Cf. A080108, A196794.
%K A196795 nonn
%O A196795 0,2
%A A196795 _Paul D. Hanna_, Oct 06 2011