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

1,1

Comments

Row 2 of A239599

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

Example

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

Crossrefs

Sequence in context: A046126 A143257 A089403 * A111674 A222505 A292356

Adjacent sequences: A239597 A239598 A239599 * A239601 A239602 A239603

Keyword

nonn

Author

R. H. Hardin, Mar 22 2014

Status

approved