A240261 Number of 2Xn 0..3 arrays with no element equal to one 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

7, 26, 102, 429, 1814, 7576, 31876, 134302, 565533, 2381951, 10034318, 42273575, 178097625, 750335259, 3161247630, 13318792242, 56114191921, 236418596411, 996073182969, 4196635500908, 17681189528630, 74494095538971

Offset

1,1

Comments

Row 2 of A240260

Links

R. H. Hardin, Table of n, a(n) for n = 1..103

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)

Example

Some solutions for n=5
..2..0..0..0..0....2..0..0..2..0....2..2..2..0..0....0..2..0..0..2
..0..2..2..3..3....0..2..2..0..2....2..0..2..2..2....2..0..2..2..2

Crossrefs

Sequence in context: A268776 A050476 A026617 * A232605 A350473 A349309

Adjacent sequences: A240258 A240259 A240260 * A240262 A240263 A240264

Keyword

nonn

Author

R. H. Hardin, Apr 03 2014

Status

approved