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 A065088 #14 Feb 24 2025 22:44:28
%S A065088 0,0,1,6,54,440,3975,38934,415324,4805856,60073245,807651350,
%T A065088 11630179506,178681848696,2918470195459,50511984152070,
%U A065088 923647710209400,17795612550034304,360361154138194809,7652375096699313126,170052779926651402990,3947014523560698353400
%N A065088 a(n) = A000166(n)*binomial(n,2).
%H A065088 Robert Israel, <a href="/A065088/b065088.txt">Table of n, a(n) for n = 0..446</a>
%p A065088 with (combstruct):with (combinat):a:=proc(m) [ZL, {ZL=Set(Cycle(Z, card>=m))}, labeled]; end: ZLL:=a(2):seq(count(ZLL, size=n)*binomial(n,2), n=0..21); # _Zerinvary Lajos_, Jun 11 2008
%t A065088 Table[Subfactorial[n]*Binomial[n, 2], {n, 0, 22}] (* _Zerinvary Lajos_, Jul 09 2009 *)
%Y A065088 Cf. A000387.
%K A065088 nonn
%O A065088 0,4
%A A065088 _N. J. A. Sloane_, Nov 10 2001