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 A180071 #23 Mar 15 2024 12:48:59
%S A180071 0,1,2,6,12,24,98,344,1236,5332,23772,110962,547714,2840028,15439466,
%T A180071 87299850,512569668,3111575102,19577613014,127331688104,852129210498,
%U A180071 5853657714546,41377621755100,300511333393982,2233952140321104
%N A180071 Number of permutations of {1..n} with the sum of squared adjacent differences < n*(n+1)/2.
%Y A180071 Cf. A180070.
%K A180071 nonn,hard
%O A180071 0,3
%A A180071 _R. H. Hardin_, Aug 09 2010
%E A180071 a(17)-a(18) from _Donovan Johnson_, Oct 11 2010
%E A180071 a(19) from _Bert Dobbelaere_, Aug 31 2020
%E A180071 a(0)-a(1) from _Alois P. Heinz_, Sep 02 2020
%E A180071 a(20)-a(23) from _Martin Ehrenstein_, Nov 12 2023
%E A180071 a(24) from _Max Alekseyev_, Mar 15 2024