A239600 Number of 2Xn 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 one plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.

3, 3, 15, 64, 244, 1030, 4303, 17923, 75264, 316087, 1329006, 5592784, 23545716, 99155410, 417639459, 1759279887, 7411361169, 31223344768, 131544340291, 554206795807, 2334940230536, 9837444241610, 41446741048349, 174622202605439

Offset: 1

Author

R. H. Hardin, Mar 22 2014

Keywords

• nonn

Comments

Row 2 of A239599

Examples

			Some solutions for n=4
..3..0..0..2....3..0..0..0....3..0..0..2....2..3..3..2....2..3..3..2
..3..2..2..0....2..3..3..2....2..3..2..2....2..1..1..2....2..1..2..2
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..98

Formula

Empirical: a(n) = 8*a(n-1) -20*a(n-2) +34*a(n-3) -111*a(n-4) +174*a(n-5) -122*a(n-6) +518*a(n-7) -341*a(n-8) -675*a(n-9) -1185*a(n-10) -967*a(n-11) +4025*a(n-12) +4959*a(n-13) +4034*a(n-14) -3986*a(n-15) -19979*a(n-16) -8427*a(n-17) -7967*a(n-18) +26414*a(n-19) +23797*a(n-20) +16119*a(n-21) +20898*a(n-22) -32421*a(n-23) -3129*a(n-24) -50644*a(n-25) -27518*a(n-26) +3200*a(n-27) -2410*a(n-28) +25372*a(n-29) +8923*a(n-30) +10252*a(n-31) +12108*a(n-32) +1635*a(n-33) -1564*a(n-34) +436*a(n-35) -2746*a(n-36) -436*a(n-37) +368*a(n-38) -998*a(n-39) -486*a(n-40) -227*a(n-41) -151*a(n-42) -21*a(n-43) -4*a(n-44) for n>47