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 A090035 #18 Dec 31 2020 02:12:48
%S A090035 1,2,3,6,10,14,19,28,42,61,85,119,161,215,293,396,506,632,788,985,
%T A090035 1194,1414,1664,1884,1999,1958,1770,1463,1076,667,361,190,88,39,19,7,1
%N A090035 Number of configurations of the 4 X 2 variant of Sam Loyd's sliding block 15-puzzle that require a minimum of n moves to be reached, starting with the empty square in one of the corners.
%C A090035 Data from Karlemo, Östergård. See corresponding link in A087725.
%D A090035 See A087725.
%H A090035 Hugo Pfoertner, <a href="http://www.randomwalk.de/sequences/sbpnx2.txt">Solutions of small n*2 sliding block puzzles.</a>
%H A090035 Takaken, <a href="http://www.ic-net.or.jp/home/takaken/nt/slide/index.html">n-Puzzle Page</a>.
%H A090035 Takaken, <a href="http://www.ic-net.or.jp/home/takaken/nt/slide/result42.txt">No. 42 (7 puzzles)</a>.
%e A090035 Starting from
%e A090035 1234
%e A090035 567-
%e A090035 the most distant configuration corresponding to a(36)=1 is
%e A090035 -721
%e A090035 4365
%o A090035 Program: See link in A089473.
%o A090035 (Python) # alst(), moves(), swap() in A089473
%o A090035 print(alst("-1234567", (4, 2))) # _Michael S. Branicky_, Dec 30 2020
%Y A090035 Cf. A087725, A089473. Index of last sequence term: A090033. Other nonsquare sliding block puzzles: A090034, A090036, A090166, A090167.
%K A090035 fini,full,nonn
%O A090035 0,2
%A A090035 _Hugo Pfoertner_, Nov 26 2003