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 A090032 #8 Jan 02 2021 14:57:06
%S A090032 1,2,4,10,26,66,171,440,1112,2786,6820,16720,41106,100856,245793,
%T A090032 597030,1441292,3469486,8304526,19832076,47110238,111669014
%N A090032 Number of configurations of the 6 X 6 variant of Sam Loyd's sliding block 15-puzzle ("35-puzzle") that require a minimum of n moves to be reached, starting with the empty square in one of the corners.
%D A090032 See A087725.
%H A090032 Hugo Pfoertner, <a href="http://www.randomwalk.de/sequences/sbpnxn.txt">Configuration counts for n*n sliding block puzzles.</a>
%o A090032 See link in A089473.
%o A090032 (Python) # uses alst(), swap() in A089473
%o A090032 start, shape = "-123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ", (6, 6)
%o A090032 print(alst(start, shape, maxd=16)) # _Michael S. Branicky_, Jan 02 2021
%Y A090032 Cf. A087725, A089473, A089484, A090031.
%K A090032 fini,hard,more,nonn
%O A090032 0,2
%A A090032 _Hugo Pfoertner_, Nov 25 2003
%E A090032 a(17)-a(21) from _Michael S. Branicky_, Dec 28 2020