OFFSET
1,1
COMMENTS
Row 5 of A211561.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = (1/384)*n^8 + (1/32)*n^7 + (95/576)*n^6 + (71/120)*n^5 + (2155/1152)*n^4 + (167/32)*n^3 + (3301/288)*n^2 + (2119/120)*n + 15.
Empirical: a(n) = sum{j in n..n+4}stirling2(n+4,j).
Conjectures from Colin Barker, Jul 19 2018: (Start)
G.f.: x*(52 - 266*x + 867*x^2 - 1367*x^3 + 1534*x^4 - 1097*x^5 + 497*x^6 - 130*x^7 + 15*x^8) / (1 - x)^9.
a(n) = 9*a(n-1) - 36*a(n-2) + 84*a(n-3) - 126*a(n-4) + 126*a(n-5) - 84*a(n-6) + 36*a(n-7) - 9*a(n-8) + a(n-9) for n>9.
(End)
EXAMPLE
Some solutions for n=5:
..0....0....0....0....0....0....0....0....0....0....0....0....0....0....0....0
..1....1....1....1....1....0....1....1....1....1....1....0....1....1....1....1
..2....1....2....2....2....1....2....2....2....2....2....1....0....2....0....2
..3....0....3....1....0....2....3....3....2....0....2....0....1....3....2....3
..4....2....2....0....3....0....4....4....3....1....1....2....2....3....2....0
..5....3....2....3....4....3....2....4....3....3....3....3....2....2....2....4
..5....2....1....3....1....4....5....1....4....3....1....3....3....4....3....1
..4....0....4....4....0....3....0....1....5....4....4....2....0....5....0....0
..1....4....5....4....2....4....0....1....3....0....0....4....4....6....4....1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 15 2012
STATUS
approved