login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A236904
Number of (n+1)X(1+1) 0..3 arrays with the maximum plus the upper median plus the minimum of every 2X2 subblock equal
1
256, 1056, 4448, 19888, 89888, 417488, 1956608, 9312576, 44619472, 215852576, 1049216928, 5132538928, 25195350544, 124226011696, 614121467712, 3045510186432, 15134214226512, 75382419526336, 376090749561824
OFFSET
1,1
COMMENTS
Column 1 of A236911
LINKS
FORMULA
Empirical: a(n) = 17*a(n-1) -19*a(n-2) -1219*a(n-3) +5945*a(n-4) +32529*a(n-5) -280951*a(n-6) -269511*a(n-7) +6755811*a(n-8) -5812177*a(n-9) -99039281*a(n-10) +203208511*a(n-11) +934230323*a(n-12) -3012311509*a(n-13) -5540751101*a(n-14) +28011237043*a(n-15) +16496390322*a(n-16) -179576775804*a(n-17) +28184896456*a(n-18) +821213209160*a(n-19) -569212593056*a(n-20) -2696245636352*a(n-21) +3123990880240*a(n-22) +6239426808528*a(n-23) -10449648214368*a(n-24) -9546555867136*a(n-25) +23780302493952*a(n-26) +7611182136960*a(n-27) -37653350578688*a(n-28) +2464568574976*a(n-29) +40926435429376*a(n-30) -14406131410944*a(n-31) -29177606928384*a(n-32) +17666861322240*a(n-33) +12348650086400*a(n-34) -11333622972416*a(n-35) -2350163591168*a(n-36) +4034882961408*a(n-37) -121760514048*a(n-38) -778041819136*a(n-39) +124775301120*a(n-40) +73936142336*a(n-41) -17637048320*a(n-42) -2604662784*a(n-43) +754974720*a(n-44)
EXAMPLE
Some solutions for n=5
..3..1....3..0....0..0....2..2....2..1....2..3....0..3....3..1....0..1....0..2
..2..3....2..3....2..3....3..1....2..3....2..1....0..3....2..2....1..2....0..3
..3..1....0..3....1..0....0..3....3..0....2..3....2..3....3..1....1..0....0..2
..3..2....3..1....3..2....3..1....3..0....1..2....1..2....2..1....2..1....3..2
..3..1....1..2....0..2....2..2....2..3....1..3....2..3....3..2....1..0....0..2
..2..3....2..3....2..3....1..3....1..2....1..2....1..2....3..0....2..0....0..3
CROSSREFS
Sequence in context: A255663 A045034 A236911 * A206198 A237218 A237212
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 01 2014
STATUS
approved