A241257 Number of 3Xn 0..3 arrays with no element equal to one plus the sum of elements to its left or zero plus the sum of the 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.
4, 17, 13, 34, 71, 135, 356, 734, 1705, 3914, 8291, 19714, 42700, 93528, 214479, 462299, 1030477, 2304077, 5035291, 11240675, 24870524, 54876698, 121998539, 269425049, 596725510, 1322494224, 2923575132, 6478965125, 14341026682
Offset: 1
Keywords
Examples
Some solutions for n=4 ..2..2..3..2....3..3..2..2....2..2..3..3....2..2..3..2....3..3..2..2 ..0..0..0..3....2..1..3..1....0..0..2..1....0..0..0..3....2..1..3..1 ..0..3..1..2....0..2..0..2....0..0..0..3....0..0..2..2....0..2..2..2
Links
- R. H. Hardin, Table of n, a(n) for n = 1..202
Formula
Empirical: a(n) = 5*a(n-2) +12*a(n-3) -10*a(n-4) -49*a(n-5) -32*a(n-6) +99*a(n-7) +157*a(n-8) -89*a(n-9) -342*a(n-10) -104*a(n-11) +431*a(n-12) +412*a(n-13) -199*a(n-14) -494*a(n-15) -154*a(n-16) -16*a(n-17) +1491*a(n-18) +1405*a(n-19) -1976*a(n-20) -3729*a(n-21) -239*a(n-22) +1932*a(n-23) +2761*a(n-24) -1387*a(n-25) +1240*a(n-26) +884*a(n-27) -1768*a(n-28) -1322*a(n-29) +738*a(n-30) -734*a(n-31) -1142*a(n-32) -314*a(n-33) +2396*a(n-34) +196*a(n-35) -1802*a(n-36) +778*a(n-37) +1882*a(n-38) -1840*a(n-39) -1356*a(n-40) +744*a(n-41) -900*a(n-42) -560*a(n-43) +220*a(n-44) -104*a(n-45) -32*a(n-46) +244*a(n-47) +24*a(n-48) -72*a(n-49) +56*a(n-50) -24*a(n-52) for n>59
Comments