A224306 Number of nX4 0..2 arrays with diagonals and rows unimodal and antidiagonals nondecreasing.

46, 698, 5996, 45453, 345875, 2717759, 22071219, 182843194, 1528645389, 12825738594, 107715455487, 904773390455, 7599493889175, 63827735783412, 536075684379248, 4502373101398007, 37814478865105363, 317596919801312214

Offset: 1

Author

R. H. Hardin Apr 03 2013

Keywords

• nonn

Comments

Column 4 of A224310

Examples

			Some solutions for n=3
..0..0..0..0....0..1..1..1....2..2..0..0....1..1..1..0....0..0..0..2
..0..0..0..1....1..2..2..2....2..2..1..0....1..2..1..1....0..0..2..2
..0..0..2..2....2..2..2..1....2..2..0..0....2..2..1..0....1..2..2..1
		

Links

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

Formula

Empirical: a(n) = 15*a(n-1) -58*a(n-2) -13*a(n-3) +160*a(n-4) +1879*a(n-5) -7373*a(n-6) +6407*a(n-7) -2233*a(n-8) +11269*a(n-9) -128277*a(n-10) +514460*a(n-11) -559176*a(n-12) +774916*a(n-13) +91024*a(n-14) -426367*a(n-15) -1572540*a(n-16) -2736461*a(n-17) -3322156*a(n-18) -10388293*a(n-19) +187424*a(n-20) -4090338*a(n-21) +4202406*a(n-22) +9112758*a(n-23) [phone]*a(n-24) [phone]*a(n-25) [phone]*a(n-26) [phone]*a(n-27) [phone]*a(n-28) [phone]*a(n-29) +483840*a(n-30) for n>35