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 A135749 #19 Aug 04 2022 07:35:53
%S A135749 1,1,3,19,217,3821,95761,3214975,137501505,7226764921,455941716481,
%T A135749 33983083953611,2954163633223969,296027886705639973,
%U A135749 33823026186790043841,4363561123325076879991,630392564294402819207041
%N A135749 a(n) = Sum_{k=0..n} binomial(n,k)*(n-k)^k*k^k.
%H A135749 G. C. Greubel, <a href="/A135749/b135749.txt">Table of n, a(n) for n = 0..250</a>
%F A135749 a(n) = n!*[x^n] Sum_{k=0..n} exp((n-k)*x)^k * x^k/k!.
%t A135749 Table[Sum[Binomial[n,k](n-k)^k k^k,{k,n}],{n,0,20}]+1 (* _Harvey P. Dale_, Oct 08 2012 *)
%o A135749 (PARI) a(n)=sum(k=0,n,binomial(n,k)*(n-k)^k*k^k)
%o A135749 (PARI) a(n)=n!*polcoeff(sum(k=0,n,exp((n-k)*k*x +x*O(x^n))*x^k/k!),n)
%Y A135749 Cf. A000248, A086331, A349965.
%K A135749 nonn
%O A135749 0,3
%A A135749 _Paul D. Hanna_, Nov 27 2007