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A185475 Number of (n+2)X9 0..2 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order.

%I A185475 #7 Jul 22 2025 09:48:26
%S A185475 336690,3212372,20411234,100908633,416227164,1497314456,4845252741,
%T A185475 14425457557,40183952539,106069534256,267851235385,651716593546,
%U A185475 1535886293189,3519099305097,7860273371841,17147427400925,36585315520514
%N A185475 Number of (n+2)X9 0..2 arrays with each 3X3 subblock having rows and columns in lexicographically nondecreasing order.
%C A185475 Column 7 of A185477
%H A185475 R. H. Hardin, <a href="/A185475/b185475.txt">Table of n, a(n) for n = 1..200</a>
%F A185475 Empirical: a(n) = (1/25519951134720000)*n^21
%F A185475 + (1/127919554560000)*n^20
%F A185475 + (1877/2551995113472000)*n^19
%F A185475 + (101861/2328135892992000)*n^18
%F A185475 + (10763959/5820339732480000)*n^17
%F A185475 + (24725641/418455797760000)*n^16
%F A185475 + (836589317/564915326976000)*n^15
%F A185475 + (22655691343/753220435968000)*n^14
%F A185475 + (5887296211331/11298306539520000)*n^13
%F A185475 + (436620904451/52672757760000)*n^12
%F A185475 + (3650470717199/28970016768000)*n^11
%F A185475 + (2036750095277/1170505728000)*n^10
%F A185475 + (1572848084986607/79009136640000)*n^9
%F A185475 + (1160407108626427/6584094720000)*n^8
%F A185475 + (2296534278781759/1975228416000)*n^7
%F A185475 + (525799308273622787/94152554496000)*n^6
%F A185475 + (25696337451699745273/1333827855360000)*n^5
%F A185475 + (2682952836795541619/55576160640000)*n^4
%F A185475 + (124299364108443341/1407929402880)*n^3
%F A185475 + (73695052155737/701719200)*n^2
%F A185475 + (1503827501467/23279256)*n
%F A185475 + 4299
%e A185475 Some solutions for 4X9
%e A185475 ..0..0..0..0..0..0..0..0..0....0..0..0..0..0..0..0..0..1
%e A185475 ..0..0..0..0..0..0..0..1..2....0..0..0..0..0..0..0..0..1
%e A185475 ..0..0..0..0..0..1..1..1..0....0..0..0..0..0..1..1..2..2
%e A185475 ..0..0..0..1..2..1..2..2..0....0..0..0..0..1..1..2..1..2
%K A185475 nonn
%O A185475 1,1
%A A185475 _R. H. Hardin_ Jan 28 2011