A232259 Number of (2+1) X (n+1) 0..2 arrays with every element both >= and <= some horizontal or antidiagonal neighbor.

37, 421, 6189, 96999, 1532151, 24091773, 379188715, 5968365535, 93937508717, 1478515964441, 23270869263099, 366268254468541, 5764822631732253, 90734534111164597, 1428102170660550681, 22477393302841813171

Offset

1,1

Comments

Row 2 of A232257.

Links

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

Formula

Empirical: a(n) = 17*a(n-1) -35*a(n-2) +251*a(n-3) -177*a(n-4) -17*a(n-5) -4903*a(n-6) +13125*a(n-7) -76030*a(n-8) +243198*a(n-9) -125167*a(n-10) +449227*a(n-11) -1759711*a(n-12) -678561*a(n-13) -14380759*a(n-14) +17235787*a(n-15) +29891739*a(n-16) +56869843*a(n-17) +17296835*a(n-18) -304146071*a(n-19) -10084543*a(n-20) +293690705*a(n-21) -289132422*a(n-22) +130389906*a(n-23) +513783546*a(n-24) -385905598*a(n-25) -127784349*a(n-26) +309897827*a(n-27) -289851977*a(n-28) -85311709*a(n-29) +219446909*a(n-30) -98649371*a(n-31) -26673126*a(n-32) +86391170*a(n-33) -33068565*a(n-34) -6799239*a(n-35) +22998341*a(n-36) -9045789*a(n-37) -3030746*a(n-38) +2050124*a(n-39) -2846970*a(n-40) -1083162*a(n-41) +282255*a(n-42) -129615*a(n-43) +66349*a(n-44) +183335*a(n-45) +17378*a(n-46) +76502*a(n-47) -4717*a(n-48) +18891*a(n-49) -5877*a(n-50) +2935*a(n-51) -1459*a(n-52) +249*a(n-53) -134*a(n-54) +8*a(n-55) -4*a(n-56) for n > 58.

Example

Some solutions for n=4
..2..2..0..2..2....1..1..0..0..2....0..0..0..1..1....0..0..2..1..1
..2..0..2..0..0....0..0..2..2..1....2..2..1..1..2....2..2..2..2..2
..1..2..0..2..2....2..2..0..0..0....0..0..2..2..2....0..0..2..2..2

Crossrefs

Cf. A232257.

Sequence in context: A090023 A254682 A232251 * A232046 A218376 A227825

Adjacent sequences: A232256 A232257 A232258 * A232260 A232261 A232262

Keyword

nonn

Author

R. H. Hardin, Nov 21 2013

Status

approved