A240194 Number of 4Xn 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or three plus the sum of the elements diagonally to its northwest, modulo 4.
4, 27, 138, 771, 5240, 40765, 336257, 2843914, 24331713, 209365217, 1806459338, 15606899530, 134920604706, 1166738652794, 10090988027354, 87282067470301, 754973088693125, 6530482231898003, 56488830699787694, 488631696598081278
Offset: 1
Keywords
Examples
Some solutions for n=4 ..2..0..0..0....2..0..0..0....2..0..0..0....2..0..0..0....2..0..0..0 ..1..2..2..0....1..0..2..2....1..2..2..2....1..2..2..2....1..0..2..0 ..2..1..1..3....1..3..2..0....2..1..2..2....2..1..2..0....1..3..2..3 ..1..3..3..2....2..3..0..0....1..3..3..2....1..3..3..2....2..1..0..2
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 27*a(n-1) -294*a(n-2) +1660*a(n-3) -4909*a(n-4) +4008*a(n-5) +28110*a(n-6) -141830*a(n-7) +316164*a(n-8) -141103*a(n-9) -1161198*a(n-10) +2896480*a(n-11) -1515959*a(n-12) -3659154*a(n-13) +5143300*a(n-14) -13602*a(n-15) -280443*a(n-16) -7998970*a(n-17) +9853042*a(n-18) +2165540*a(n-19) -18119292*a(n-20) +21393552*a(n-21) -1551144*a(n-22) -20485792*a(n-23) +14878784*a(n-24) +4182464*a(n-25) -7981312*a(n-26) +1462784*a(n-27) +1097728*a(n-28) -368640*a(n-29) for n>34
Comments