A241249 Number of nX2 0..3 arrays with no element equal to one plus the sum of elements to its left or zero plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest or zero plus the sum of the elements antidiagonally to its northeast, modulo 4.
3, 5, 17, 39, 87, 212, 488, 1134, 2644, 6118, 14205, 32964, 76395, 177149, 410798, 952422, 2208198, 5120116, 11871494, 27525169, 63821315, 147978217, 343107782, 795547902, 1844596244, 4276972393, 9916824861, 22993686321, 53314396437
Offset: 1
Keywords
Examples
Some solutions for n=4 ..3..3....3..3....2..2....2..2....2..2....3..3....3..2....2..2....3..3....2..2 ..2..1....2..2....3..1....3..1....3..1....2..1....0..3....3..1....2..2....3..1 ..3..1....0..2....0..2....3..1....3..2....0..2....0..2....3..1....3..2....2..1 ..3..3....3..2....3..3....3..2....3..2....0..3....0..2....2..1....3..1....2..2
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 3*a(n-2) +14*a(n-3) +5*a(n-4) -28*a(n-5) -89*a(n-6) -50*a(n-7) +93*a(n-8) +303*a(n-9) +214*a(n-10) -113*a(n-11) -561*a(n-12) -468*a(n-13) -47*a(n-14) +584*a(n-15) +499*a(n-16) +142*a(n-17) -359*a(n-18) -96*a(n-19) -23*a(n-20) +128*a(n-21) -102*a(n-22) -99*a(n-23) -119*a(n-24) +32*a(n-25) +82*a(n-26) +113*a(n-27) +50*a(n-28) -7*a(n-29) -42*a(n-30) -20*a(n-31) +a(n-32) +4*a(n-33) +a(n-34) for n>37
Comments