A247529 Number of length n+3 0..4 arrays with some disjoint pairs in every consecutive four terms having the same sum.

185, 317, 561, 1007, 1823, 3455, 6495, 12105, 22459, 43255, 82157, 154279, 287847, 556213, 1059205, 1992823, 3723991, 7202379, 13726813, 25838725, 48308217, 93456427, 178172281, 335410643, 627185919, 1213463869, 2313820457, 4355601755

Offset: 1

Author

R. H. Hardin, Sep 18 2014

Keywords

• nonn

Comments

Column 4 of A247533

Examples

			Some solutions for n=6
..0....3....0....1....4....3....4....3....1....3....0....1....3....2....4....0
..1....4....4....2....1....2....2....4....0....2....3....0....0....4....1....0
..3....0....1....0....2....1....1....1....2....4....1....2....4....1....0....2
..4....1....3....1....3....2....3....0....3....1....2....1....1....3....3....2
..2....3....2....1....4....3....2....3....1....3....2....1....3....0....2....4
..1....4....2....2....1....4....2....2....2....0....3....2....2....2....1....0
..3....2....1....2....2....1....3....1....2....2....1....0....2....1....2....2
..2....3....1....1....3....0....1....2....3....1....0....3....3....1....3....2
..4....3....0....3....4....3....4....1....1....1....4....1....1....0....4....0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = a(n-1) +4*a(n-2) -4*a(n-3) +18*a(n-4) -18*a(n-5) -78*a(n-6) +78*a(n-7) -67*a(n-8) +67*a(n-9) +386*a(n-10) -386*a(n-11) +22*a(n-12) -22*a(n-13) -686*a(n-14) +686*a(n-15) +125*a(n-16) -125*a(n-17) +616*a(n-18) -616*a(n-19) -178*a(n-20) +178*a(n-21) -340*a(n-22) +340*a(n-23) +130*a(n-24) -130*a(n-25) +80*a(n-26) -80*a(n-27) -40*a(n-28) +40*a(n-29) for n>30