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A203437 Number of nX2 0..7 arrays with every nonzero element less than or equal to at least two horizontal and vertical neighbors 1
1, 8, 64, 372, 2528, 21988, 186348, 1484834, 11983672, 99287560, 822775984, 6775991390, 55862871172, 461924799782, 3821399789826, 31599121605851, 261335463668876, 2162179173512322, 17891459865015592, 148048457731612474 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 2 of A203443

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 36*a(n-1) -602*a(n-2) +6524*a(n-3) -53347*a(n-4) +352422*a(n-5) -1940764*a(n-6) +9153172*a(n-7) -37752485*a(n-8) +137893274*a(n-9) -452055467*a(n-10) +1342970830*a(n-11) -3638057933*a(n-12) +9071693523*a(n-13) -20876148243*a(n-14) +44616933604*a(n-15) -89039926643*a(n-16) +165518375256*a(n-17) -290731468771*a(n-18) +476018515556*a(n-19) -741344186335*a(n-20) +1086274377944*a(n-21) -1492483448334*a(n-22) +2010607579832*a(n-23) -2375704774615*a(n-24) +3083242158195*a(n-25) -2965069704481*a(n-26) +3977509164220*a(n-27) -2865245806362*a(n-28) +4282022816454*a(n-29) -2209936530089*a(n-30) +3563239284535*a(n-31) -1810789629749*a(n-32) +1541595407413*a(n-33) -2532133018233*a(n-34) -1528699238219*a(n-35) -4363095870912*a(n-36) -4657280718765*a(n-37) -6241687618075*a(n-38) -6583983672912*a(n-39) -6941720583956*a(n-40) -6657522110347*a(n-41) -6088912229602*a(n-42) -5251969355432*a(n-43) -4291270339013*a(n-44) -3336195568667*a(n-45) -2461322964502*a(n-46) -1730540685280*a(n-47) -1157304679412*a(n-48) -737378430538*a(n-49) -447345400723*a(n-50) -258349758641*a(n-51) -142008774910*a(n-52) -74211080092*a(n-53) -36849518988*a(n-54) -17360164987*a(n-55) -7748606740*a(n-56) -3270826347*a(n-57) -1302550490*a(n-58) -488139432*a(n-59) -171539870*a(n-60) -56301911*a(n-61) -17173472*a(n-62) -4836189*a(n-63) -1247724*a(n-64) -291715*a(n-65) -60925*a(n-66) -11148*a(n-67) -1730*a(n-68) -217*a(n-69) -20*a(n-70) -a(n-71)

EXAMPLE

Some solutions for n=5

..1..1....0..0....4..4....5..5....2..2....5..5....0..0....5..5....1..1....3..3

..4..4....5..5....4..4....7..7....5..5....5..5....1..1....5..5....1..1....3..3

..4..4....6..6....6..6....7..7....5..5....3..1....4..4....3..3....4..4....1..0

..5..5....6..6....6..6....1..1....0..0....3..3....6..6....1..1....4..4....4..4

..5..5....0..0....4..4....0..0....0..0....3..3....6..6....0..0....2..2....4..4

CROSSREFS

Sequence in context: A225014 A228460 A202909 * A224132 A297376 A293888

Adjacent sequences:  A203434 A203435 A203436 * A203438 A203439 A203440

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 01 2012

STATUS

approved

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Last modified January 28 22:30 EST 2022. Contains 350669 sequences. (Running on oeis4.)