|
%I #4 Jul 04 2013 07:26:07
%S 5,30,132,513,1949,7131,24496,78761,238146,681095,1852355,4813290,
%T 11999195,28801351,66769946,149914163,326768708,692941231,1432287640,
%U 2890510485,5704099317,11022017108,20880164204,38823463828,70923212058
%N Number of nX4 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X5 binary array having a sum of three or less, with rows and columns of the latter in lexicographically nondecreasing order
%C Column 4 of A227269
%H R. H. Hardin, <a href="/A227267/b227267.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = (1/121645100408832000)*n^19 + (1/6402373705728000)*n^18 + (23/1067062284288000)*n^17 + (31/62768369664000)*n^16 + (37/5706215424000)*n^15 + (4111/5706215424000)*n^14 - (301079/47076277248000)*n^13 + (126941/452656512000)*n^12 + (14792293/9656672256000)*n^11 - (78942259/877879296000)*n^10 + (13084929349/4828336128000)*n^9 - (165214115519/4828336128000)*n^8 + (5087156753417/23538138624000)*n^7 + (3282017247319/2942267328000)*n^6 - (4087118559803/118879488000)*n^5 + (37821361216913/118879488000)*n^4 - (460675235565641/308756448000)*n^3 + (19317471160409/6175128960)*n^2 + (109108917509/232792560)*n - 9102 for n>7
%e Some solutions for n=4
%e ..1..1..1..1....1..1..1..0....1..1..1..1....1..1..1..1....1..1..1..0
%e ..1..1..1..0....1..1..1..1....1..1..1..1....1..1..0..0....1..1..0..0
%e ..1..0..1..1....0..1..1..1....1..1..0..1....1..0..0..0....1..1..0..0
%e ..0..0..1..1....0..1..1..0....1..1..1..1....1..1..1..1....1..0..0..0
%K nonn
%O 1,1
%A _R. H. Hardin_ Jul 04 2013
| 