cp's OEIS Frontend

A184566 Number of (n+2)X3 0..3 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order.

%I A184566 #7 Jul 22 2025 09:37:32
%S A184566 14178,102445,545662,2430950,9496395,33351260,107058241,318063303,
%T A184566 883398416,2312834051,5747404508,13634816674,31030883261,68030181122,
%U A184566 144179542873,296289041222,591935421670,1152308627603,2190104262402
%N A184566 Number of (n+2)X3 0..3 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order.
%C A184566 Column 1 of A184574
%H A184566 R. H. Hardin, <a href="/A184566/b184566.txt">Table of n, a(n) for n = 1..200</a>
%F A184566 Empirical: a(n) = (1/121645100408832000)*n^19
%F A184566 + (53/3201186852864000)*n^18
%F A184566 + (5743/2134124568576000)*n^17
%F A184566 + (12931/62768369664000)*n^16
%F A184566 + (621041/62768369664000)*n^15
%F A184566 + (10734523/31384184832000)*n^14
%F A184566 + (1720232317/188305108992000)*n^13
%F A184566 + (127448011/658409472000)*n^12
%F A184566 + (6294370109/1931334451200)*n^11
%F A184566 + (18970604773/438939648000)*n^10
%F A184566 + (4321841102639/9656672256000)*n^9
%F A184566 + (17491957547611/4828336128000)*n^8
%F A184566 + (1086794057312713/47076277248000)*n^7
%F A184566 + (2752481070552527/23538138624000)*n^6
%F A184566 + (1237909924891457/2615348736000)*n^5
%F A184566 + (1921023328483453/1307674368000)*n^4
%F A184566 + (249101413506019/77189112000)*n^3
%F A184566 + (12857906145353/2806876800)*n^2
%F A184566 + (288855292519/77597520)*n
%F A184566 + 561
%e A184566 Some solutions for 4X3
%e A184566 ..0..1..3....0..1..1....0..0..2....0..0..0....0..1..3....0..0..3....0..1..1
%e A184566 ..0..2..3....0..1..2....0..1..2....1..1..3....0..3..3....0..1..3....1..1..1
%e A184566 ..3..2..3....2..2..3....3..0..0....1..2..0....2..0..0....0..3..3....1..2..3
%e A184566 ..3..3..1....2..3..1....3..3..1....3..0..0....3..1..3....2..0..1....2..1..0
%K A184566 nonn
%O A184566 1,1
%A A184566 _R. H. Hardin_ Jan 17 2011