A223860 - OEIS

%I #6 Sep 07 2022 11:52:33

%S 130,3526,41682,315124,1771012,8008548,30627033,102479569,307435001,

%T 842078930,2135465204,5069027730,11361881611,24219158218,49385314943,

%U 96803565005,183160193142,335692581558,597766839750,1036890170376

%N Number of n X 4 0..3 arrays with rows and antidiagonals unimodal and columns nondecreasing.

%C Column 4 of A223864.

%H R. H. Hardin, <a href="/A223860/b223860.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = (3551/47900160)*n^12 + (3551/1995840)*n^11 + (100307/4354560)*n^10 + (28081/145152)*n^9 + (1559477/1451520)*n^8 + (14951/3456)*n^7 + (54414629/4354560)*n^6 + (18845069/725760)*n^5 + (41975947/1088640)*n^4 + (7155619/181440)*n^3 + (694249/83160)*n^2 - (7351/990)*n - 11 for n>1.

%e Some solutions for n=3

%e ..0..1..1..1....1..2..3..0....0..1..2..0....0..3..0..0....0..1..1..0

%e ..3..2..2..1....1..2..3..3....1..2..3..1....2..3..0..0....0..2..1..0

%e ..3..3..2..1....2..2..3..3....2..2..3..1....3..3..1..0....0..3..3..3

%Y Cf. A223864.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 28 2013