A200158 Number of 0..n arrays x(0..6) of 7 elements with zero 6th difference.
2, 45, 182, 685, 2036, 5153, 11370, 23035, 43284, 76523, 129052, 208597, 324900, 491519, 723994, 1041095, 1467042, 2029069, 2759166, 3697749, 4888510, 6381185, 8237500, 10523625, 13313648, 16697587, 20769202, 25633157, 31415424, 38246327
Offset: 1
Keywords
Examples
Some solutions for n=6 ..1....3....1....4....0....2....1....5....0....2....2....1....5....5....2....0 ..6....0....1....6....6....5....5....6....3....1....0....6....3....0....0....6 ..5....1....6....3....3....3....0....0....2....0....3....6....0....3....2....2 ..2....1....5....4....1....2....0....1....2....2....1....3....3....5....1....1 ..0....1....1....6....2....3....2....4....2....3....0....2....5....4....1....4 ..1....3....0....4....4....4....1....2....1....1....5....5....1....2....5....6 ..6....5....0....1....5....2....5....3....4....5....3....5....4....2....3....2
Links
- R. H. Hardin, Table of n, a(n) for n = 1..200
Formula
Empirical: a(n) = 2*a(n-1) -a(n-2) +2*a(n-6) -4*a(n-7) +2*a(n-8) -a(n-12) +2*a(n-13) -a(n-14) +2*a(n-15) -4*a(n-16) +2*a(n-17) +a(n-20) -6*a(n-21) +9*a(n-22) -4*a(n-23) -2*a(n-26) +6*a(n-27) -6*a(n-28) +2*a(n-29) -a(n-30) +2*a(n-31) -2*a(n-33) +a(n-34) -2*a(n-35) +6*a(n-36) -6*a(n-37) +2*a(n-38) +4*a(n-41) -9*a(n-42) +6*a(n-43) -a(n-44) -2*a(n-47) +4*a(n-48) -2*a(n-49) +a(n-50) -2*a(n-51) +a(n-52) -2*a(n-56) +4*a(n-57) -2*a(n-58) +a(n-62) -2*a(n-63) +a(n-64)
Comments