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 A263643 #4 Oct 22 2015 14:48:29 %S A263643 1,1,2,1,2,2,1,2,5,2,1,2,5,9,2,1,2,5,17,11,2,1,2,5,17,41,19,2,1,2,5, %T A263643 17,70,75,27,2,1,2,5,17,70,226,156,44,2,1,2,5,17,70,349,538,340,65,2, %U A263643 1,2,5,17,70,349,1389,1417,738,104,2,1,2,5,17,70,349,2017,4255,3734,1567,155,2 %N A263643 T(n,k)=Number of length n arrays of permutations of 0..n-1 with each element moved by -k to k places and with no two consecutive increases. %C A263643 Table starts %C A263643 .1...1....1.....1.....1......1......1......1......1......1......1......1......1 %C A263643 .2...2....2.....2.....2......2......2......2......2......2......2......2......2 %C A263643 .2...5....5.....5.....5......5......5......5......5......5......5......5......5 %C A263643 .2...9...17....17....17.....17.....17.....17.....17.....17.....17.....17.....17 %C A263643 .2..11...41....70....70.....70.....70.....70.....70.....70.....70.....70.....70 %C A263643 .2..19...75...226...349....349....349....349....349....349....349....349....349 %C A263643 .2..27..156...538..1389...2017...2017...2017...2017...2017...2017...2017...2017 %C A263643 .2..44..340..1417..4255...9673..13358..13358..13358..13358..13358..13358..13358 %C A263643 .2..65..738..3734.13529..36321..74678..99377..99377..99377..99377..99377..99377 %C A263643 .2.104.1567.10564.42700.138420.335720.636645.822041.822041.822041.822041.822041 %H A263643 R. H. Hardin, <a href="/A263643/b263643.txt">Table of n, a(n) for n = 1..484</a> %F A263643 Empirical for column k: %F A263643 k=2: a(n) = 2*a(n-2) +a(n-3) -a(n-5) for n>9 %F A263643 k=3: [order 14] for n>19 %F A263643 k=4: [order 46] for n>53 %e A263643 Some solutions for n=6 k=4 %e A263643 ..2....2....3....0....2....3....3....4....1....4....1....4....4....0....4....1 %e A263643 ..0....1....0....5....5....1....4....0....4....5....5....2....3....5....1....0 %e A263643 ..4....4....2....1....3....5....2....2....0....2....4....5....5....2....0....4 %e A263643 ..1....0....1....3....0....0....5....1....3....0....0....3....0....3....5....3 %e A263643 ..5....5....5....2....4....4....0....5....2....3....3....0....2....1....2....5 %e A263643 ..3....3....4....4....1....2....1....3....5....1....2....1....1....4....3....2 %Y A263643 Diagonal is A049774. %K A263643 nonn,tabl %O A263643 1,3 %A A263643 _R. H. Hardin_, Oct 22 2015