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 A263905 #4 Oct 29 2015 07:45:14 %S A263905 1,1,2,1,2,3,1,2,6,5,1,2,6,13,8,1,2,6,20,31,13,1,2,6,20,61,73,21,1,2, %T A263905 6,20,76,185,172,34,1,2,6,20,76,269,577,399,55,1,2,6,20,76,300,979, %U A263905 1788,932,89,1,2,6,20,76,300,1189,3552,5540,2177,144,1,2,6,20,76,300,1252 %N A263905 T(n,k)=Number of length n arrays of permutations of 0..n-1 with each element moved by -k to k places and the total absolute value of displacements not greater than 2*(n-1). %C A263905 Table starts %C A263905 ..1....1.....1.....1.....1.....1.....1......1......1......1......1......1 %C A263905 ..2....2.....2.....2.....2.....2.....2......2......2......2......2......2 %C A263905 ..3....6.....6.....6.....6.....6.....6......6......6......6......6......6 %C A263905 ..5...13....20....20....20....20....20.....20.....20.....20.....20.....20 %C A263905 ..8...31....61....76....76....76....76.....76.....76.....76.....76.....76 %C A263905 .13...73...185...269...300...300...300....300....300....300....300....300 %C A263905 .21..172...577...979..1189..1252..1252...1252...1252...1252...1252...1252 %C A263905 .34..399..1788..3552..4701..5197..5324...5324...5324...5324...5324...5324 %C A263905 .55..932..5540.13068.18754.21735.22869..23124..23124..23124..23124..23124 %C A263905 .89.2177.17165.47999.75243.91151.98497.101037.101548.101548.101548.101548 %H A263905 R. H. Hardin, <a href="/A263905/b263905.txt">Table of n, a(n) for n = 1..617</a> %F A263905 Empirical for column k: %F A263905 k=1: a(n) = a(n-1) +a(n-2) %F A263905 k=2: a(n) = 2*a(n-1) +2*a(n-3) +a(n-4) -3*a(n-5) -2*a(n-7) +a(n-9) %e A263905 Some solutions for n=7 k=4 %e A263905 ..3....0....3....2....4....0....3....0....0....1....4....0....3....0....2....1 %e A263905 ..0....3....1....1....1....1....1....5....1....3....0....2....0....2....1....3 %e A263905 ..2....1....5....5....0....3....0....3....4....2....2....1....4....4....4....2 %e A263905 ..6....4....2....0....3....2....6....4....5....6....1....5....2....1....0....6 %e A263905 ..1....5....0....3....6....4....4....1....6....0....5....6....5....3....6....0 %e A263905 ..4....6....4....4....2....5....2....2....2....4....6....4....1....6....5....5 %e A263905 ..5....2....6....6....5....6....5....6....3....5....3....3....6....5....3....4 %Y A263905 Column 1 is A000045(n+1). %K A263905 nonn,tabl %O A263905 1,3 %A A263905 _R. H. Hardin_, Oct 29 2015