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 A352847 #16 Apr 22 2022 04:39:29
%S A352847 0,0,48,576,3840,19200,80640,301056,1032192,3317760,10137600,29736960,
%T A352847 84344832,232587264,626196480,1651507200,4278190080,10909384704,
%U A352847 27433893888,68136468480,167352729600,406931374080,980510834688,2343038877696,5556613939200
%N A352847 Number of copies of the star graph S(2,1,1) contained within the n-dimensional hypercube graph.
%C A352847 The star graph S(2,1,1) is the unique tree with degree sequence 3,2,1,1,1.
%H A352847 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (10,-40,80,-80,32).
%F A352847 a(n) = 2^n*binomial(n,2)*(n-1)*(n-2).
%F A352847 G.f.: 48*x^3*(1 + 2*x)/(1 - 2*x)^5. - _Stefano Spezia_, Apr 15 2022
%F A352847 Sum_{n>=3} 1/a(n) = 9/8 + log(2)^2/2 - 3*log(2)/4 - Pi^2/12. - _Amiram Eldar_, Apr 22 2022
%t A352847 a[n_] := (2^n)*Binomial[n,2]*(n-1)*(n-2); Array[a, 25] (* _Amiram Eldar_, Apr 22 2022 *)
%o A352847 (Python) from math import comb
%o A352847 def a(n):
%o A352847 return (2**n)*comb(n,2)*(n-2)*(n-1)
%Y A352847 Cf. A129002.
%K A352847 nonn,easy
%O A352847 1,3
%A A352847 _Ben Eck_, Apr 05 2022