A263595 Number of length n arrays of permutations of 0..n-1 with each element moved by -6 to 6 places and the median of every three consecutive elements nondecreasing.
1, 2, 6, 16, 52, 208, 800, 2900, 10960, 40792, 148288, 544600, 2000084, 7312332, 26795812, 98234356, 359845004, 1319030780, 4834945864, 17718152672, 64944710636, 238041386504, 872396576888, 3197533964256, 11719620057508
Offset: 1
Keywords
Examples
Some solutions for n=6 ..2....4....1....1....5....0....0....4....1....0....2....0....1....1....0....1 ..3....0....2....0....0....2....2....0....2....2....5....1....0....0....3....0 ..0....1....0....2....1....3....1....1....5....4....0....3....2....5....1....3 ..4....3....4....5....3....4....4....5....3....1....3....2....5....2....4....2 ..5....2....5....4....2....1....5....3....0....3....4....4....3....3....5....4 ..1....5....3....3....4....5....3....2....4....5....1....5....4....4....2....5
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A263597.
Formula
Empirical: a(n) = a(n-1) +a(n-2) +27*a(n-3) +11*a(n-4) +19*a(n-5) -17*a(n-6) +55*a(n-7) +207*a(n-8) +399*a(n-9) +842*a(n-10) +4810*a(n-11) +7064*a(n-12) -5048*a(n-13) -11662*a(n-14) +10885*a(n-15) -23133*a(n-16) -24495*a(n-17) +19889*a(n-18) -61624*a(n-19) -96905*a(n-20) -82792*a(n-21) -121206*a(n-22) -43903*a(n-23) -440813*a(n-24) -321679*a(n-25) +36248*a(n-26) -1481424*a(n-27) -184710*a(n-28) -147760*a(n-29) -954886*a(n-30) -1689620*a(n-31) +910782*a(n-32) -876748*a(n-33) -1449360*a(n-34) +1330892*a(n-35) +2445848*a(n-36) -1219064*a(n-37) +1399100*a(n-38) +2785232*a(n-39) +286256*a(n-40) +544140*a(n-41) +1489220*a(n-42) -40800*a(n-43) -524376*a(n-44) -119768*a(n-45) -395576*a(n-46) +110160*a(n-47) +418424*a(n-48) +649656*a(n-49) -332096*a(n-50) +215424*a(n-51) +84720*a(n-52) -2800*a(n-53) +293600*a(n-54) -3744*a(n-55) +128256*a(n-56) +40704*a(n-57) +10944*a(n-58) +11712*a(n-59) +2176*a(n-60) +9472*a(n-61) -1664*a(n-62) +3840*a(n-63) -2816*a(n-64) -256*a(n-65) -512*a(n-67)
Comments