A245955 Number of length 5+3 0..n arrays with some pair in every consecutive four terms totalling exactly n.
162, 4145, 26244, 128649, 381222, 1021225, 2217096, 4555697, 8345130, 14757441, 24276492, 38959225, 59493294, 89187449, 128950032, 183778785, 254805426, 349227217, 468384660, 622261481, 812372022, 1052152905, 1343233944
Offset: 1
Keywords
Examples
Some solutions for n=4 ..2....4....0....1....1....3....1....1....3....3....2....0....0....3....0....4 ..2....0....4....2....1....0....1....3....1....0....1....1....2....0....4....0 ..3....4....0....2....4....3....1....0....2....3....4....2....1....2....2....4 ..2....4....4....2....3....4....3....1....4....1....3....3....3....4....4....1 ..1....0....0....4....1....3....2....3....0....1....1....2....1....4....2....2 ..2....4....3....3....3....1....1....0....3....0....2....4....3....0....2....0 ..3....1....4....1....4....4....2....0....1....4....0....2....1....1....2....4 ..1....3....0....4....4....0....0....1....3....0....2....2....3....2....3....0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 2*a(n-1) +4*a(n-2) -10*a(n-3) -5*a(n-4) +20*a(n-5) -20*a(n-7) +5*a(n-8) +10*a(n-9) -4*a(n-10) -2*a(n-11) +a(n-12)
Comments