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 A355464 #15 Jul 03 2022 09:34:57
%S A355464 1,2,4,17,210,9217,1399298,811229225,2071392232962,20710319937493889,
%T A355464 1137259214532706572162,255141201504146525745627265,
%U A355464 348787971214016591166179037803522,2262996819897931095524655885144485185409
%N A355464 Expansion of Sum_{k>=0} x^k/(1 - k^k * x)^(k+1).
%F A355464 E.g.f.: Sum_{k>=0} exp(k^k * x) * x^k/k!.
%F A355464 a(n) = Sum_{k=0..n} k^(k*(n-k)) * binomial(n,k).
%o A355464 (PARI) my(N=20, x='x+O('x^N)); Vec(sum(k=0, N, x^k/(1-k^k*x)^(k+1)))
%o A355464 (PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(sum(k=0, N, exp(k^k*x)*x^k/k!)))
%o A355464 (PARI) a(n) = sum(k=0, n, k^(k*(n-k))*binomial(n, k));
%Y A355464 Cf. A086331, A320287, A349893, A355440, A355463.
%Y A355464 Cf. A000248, A135746, A355473.
%K A355464 nonn
%O A355464 0,2
%A A355464 _Seiichi Manyama_, Jul 03 2022