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 A223827 Number of n X 4 0..2 arrays with rows and columns unimodal. 1

%I #6 Mar 01 2023 13:38:43

%S 46,2116,51136,738482,7291180,54035194,320423509,1590193515,

%T 6823643014,25942390362,89032405314,279892497568,815488308996,

%U 2223043463584,5714420877205,13941660959025,32460302492138,72461547637300

%N Number of n X 4 0..2 arrays with rows and columns unimodal.

%C Column 4 of A223831.

%H R. H. Hardin, <a href="/A223827/b223827.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = (456419/5230697472000)*n^16 + (35741/12108096000)*n^15 + (154711/2874009600)*n^14 + (1309129/2075673600)*n^13 + (149137159/28740096000)*n^12 + (924691/29568000)*n^11 + (261112321/1828915200)*n^10 + (17095201/33868800)*n^9 + (7372850867/5225472000)*n^8 + (227410163/72576000)*n^7 + (8054484973/1437004800)*n^6 + (6610049/831600)*n^5 + (112396487393/12108096000)*n^4 + (4125505841/504504000)*n^3 + (671183/110880)*n^2 + (27067/10010)*n + 1.

%e Some solutions for n=3

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

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

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

%Y Cf. A223831.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 27 2013

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Last modified April 23 00:33 EDT 2024. Contains 371906 sequences. (Running on oeis4.)