A278379 - OEIS

%I #6 Dec 15 2021 19:01:27

%S 0,0,3,40,267,1350,5936,23565,84912,278422,835824,2316601,5980937,

%T 14503972,33282396,72732358,152195016,306378420,595704701,1122541470,

%U 2056128263,3670127802,6398217740,10915088955,18252749400,29965289850

%N Number of n X 2 0..1 arrays with rows and columns in lexicographic nondecreasing order but with exactly three mistakes.

%C Column 2 of A278385.

%H R. H. Hardin, <a href="/A278379/b278379.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = (1/1307674368000)*n^15 + (1/12454041600)*n^14 + (149/37362124800)*n^13 + (31/319334400)*n^12 + (1517/1306368000)*n^11 + (169/87091200)*n^10 - (73537/1828915200)*n^9 - (3971/87091200)*n^8 + (2939219/653184000)*n^7 + (521/2419200)*n^6 - (1516673/44906400)*n^5 - (19007/59875200)*n^4 + (351393113/4540536000)*n^3 + (3149/21621600)*n^2 - (5/104)*n.

%e Some solutions for n=4

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

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

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

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

%Y Cf. A278385.

%K nonn

%O 1,3

%A _R. H. Hardin_, Nov 20 2016