A245950 T(n,k)=Number of length n+3 0..k arrays with some pair in every consecutive four terms totalling exactly k.
14, 71, 26, 196, 197, 48, 453, 676, 545, 88, 834, 1889, 2304, 1501, 162, 1435, 3966, 7769, 7744, 4145, 298, 2216, 7669, 18384, 31465, 26244, 11441, 548, 3305, 13064, 39721, 82968, 128649, 88804, 31577, 1008, 4630, 21281, 73728, 199141, 381222
Offset: 1
Examples
Some solutions for n=4 k=4 ..1....4....0....2....1....3....3....0....3....2....0....4....0....3....2....2 ..3....2....1....1....4....2....1....4....0....4....1....0....4....4....0....2 ..3....2....4....3....0....2....1....1....4....1....4....3....4....2....2....2 ..2....1....2....0....0....0....4....0....3....3....3....1....3....1....2....0 ..1....3....0....1....3....4....3....2....2....2....0....1....0....0....2....4 ..3....4....3....0....1....2....1....3....0....1....1....4....2....3....1....1 ..1....2....1....4....0....3....1....2....1....4....1....0....1....1....1....4
Links
- R. H. Hardin, Table of n, a(n) for n = 1..9999
Formula
Empirical for column k:
k=1: a(n) = a(n-1) +a(n-2) +a(n-3)
k=2: a(n) = 2*a(n-1) +2*a(n-2) +a(n-3) -a(n-4) -2*a(n-5) -2*a(n-6) -a(n-7) +a(n-8) +a(n-9)
k=3: a(n) = 2*a(n-1) +3*a(n-2) +6*a(n-3) -a(n-4) -a(n-6)
k=4: [order 15]
k=5: a(n) = 3*a(n-1) +5*a(n-2) +13*a(n-3) -13*a(n-4) -a(n-5) -3*a(n-6) +a(n-7)
k=6: [order 16]
k=7: a(n) = 3*a(n-1) +9*a(n-2) +31*a(n-3) -19*a(n-4) -3*a(n-5) -5*a(n-6) +a(n-7)
k=8: [order 16]
k=9: a(n) = 3*a(n-1) +13*a(n-2) +57*a(n-3) -25*a(n-4) -5*a(n-5) -7*a(n-6) +a(n-7)
Empirical for row n:
n=1: a(n) = 2*a(n-1) +a(n-2) -4*a(n-3) +a(n-4) +2*a(n-5) -a(n-6)
n=2: a(n) = 2*a(n-1) +2*a(n-2) -6*a(n-3) +6*a(n-5) -2*a(n-6) -2*a(n-7) +a(n-8)
n=3: a(n) = 3*a(n-1) -8*a(n-3) +6*a(n-4) +6*a(n-5) -8*a(n-6) +3*a(n-8) -a(n-9)
n=4: [order 10]
n=5: [order 12]
n=6: [order 13]
n=7: [order 14]
Comments