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 A118795 #17 Mar 04 2018 03:06:06
%S A118795 0,1,4,29,329,5172,104335,2571473,74894818,2516911731,95862252417,
%T A118795 4080739041238,192000366357981,9894168501171229,554208686184384028,
%U A118795 33527021385789228265,2178482569432714859789,151314182463701892157460,11188187745418763137485747
%N A118795 E.g.f.: -1 + exp(( 1 - sqrt(5 - 4*exp(x)) )/2).
%C A118795 Also equals the unsigned row sums of triangle A118793 (offset without leading zero).
%F A118795 a(n) = (n-1)!*Sum_{k=0..n-1} abs( [x^k] (x/log(1-x-x^2))^n/(n-1-k)! ) for n>0.
%F A118795 a(n) = sum(k=1..n, (sum(i=0..n-k, ((i+k-1)!*C(k+2*i-1,i+k-1) *stirling2(n, i+k))))/(k-1)!). - _Vladimir Kruchinin_, Nov 22 2011
%F A118795 a(n) ~ sqrt(5) * n^(n-1) / (2^(3/2) * exp(n-1/2) * (log(5/4))^(n-1/2)). - _Vaclav Kotesovec_, Jul 14 2014
%e A118795 E.g.f.: A(x) = x + (4/2)*x^2 + (29/6)*x^3 + (329/24)*x^4 + (5172/120)*x^5 + ...
%t A118795 CoefficientList[Series[-1 + E^((1-Sqrt[5-4*E^x])/2), {x, 0, 20}], x] * Range[0, 20]! (* _Vaclav Kotesovec_, Jul 14 2014 *)
%o A118795 (PARI) a(n)=local(x=X+X^2*O(X^n));n!*polcoeff(-1+exp((1-sqrt(5-4*exp(x)))/2),n,X)
%o A118795 (PARI) /* As the unsigned row sums of A118793: */ a(n)=local(x=X+X^2*O(X^n));if(n<1,0, (n-1)!*sum(k=0,n-1,abs(polcoeff(((x/log(1-x-x^2)))^n/(n-1-k)!,k,X))))
%o A118795 (Maxima) a(n):=sum((sum(((i+k-1)!*binomial(k+2*i-1,i+k-1)*stirling2(n,i+k)), i,0,n-k))/(k-1)!,k,1,n); /* _Vladimir Kruchinin_, Nov 22 2011 */
%Y A118795 Cf. A118793, A118794.
%K A118795 nonn
%O A118795 0,3
%A A118795 _Paul D. Hanna_, Apr 30 2006