login
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
1
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
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
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 03 2014
STATUS
approved