A227261 Number of n X 4 0,1 arrays indicating 2 X 2 subblocks of some larger (n+1) X 5 binary array having a sum of two or less, with rows and columns of the latter in lexicographically nondecreasing order.

5, 50, 353, 2201, 11932, 57146, 244818, 951917, 3403038, 11297855, 35123154, 102968348, 286360987, 759331583, 1928166887, 4706232142, 11076831313, 25210805133, 55622829033, 119222502647, 248739253915, 506020952898

Offset: 1

Author

R. H. Hardin, Jul 04 2013

Keywords

• nonn

Comments

Column 4 of A227263.

Examples

			Some solutions for n=4
..1..0..0..0....1..1..1..0....1..1..0..0....1..1..1..0....1..1..1..1
..1..1..1..0....1..1..0..0....1..0..0..0....1..1..1..0....1..1..1..0
..1..1..1..1....1..0..0..0....1..0..1..1....1..1..1..0....0..0..0..0
..1..1..1..1....1..1..0..0....1..0..1..1....1..0..1..1....0..0..0..1
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210

Crossrefs

Cf. A227263.

Formula

Empirical: a(n) = (1/1689515283456000)*n^19 + (43/1067062284288000)*n^18 + (1/1097800704000)*n^17 + (1/24908083200)*n^16 + (2161/2615348736000)*n^15 + (7723/10461394944000)*n^14 + (76931/201180672000)*n^13 + (38351/48283361280)*n^12 - (9767641/402361344000)*n^11 + (9434683/6967296000)*n^10 - (3668820107/402361344000)*n^9 - (5124736597/80472268800)*n^8 + (150774753091/72648576000)*n^7 - (42587741190289/3923023104000)*n^6 - (18276563116219/163459296000)*n^5 + (6577553955799/3113510400)*n^4 - (743180805841567/51459408000)*n^3 + (63341814516853/1286485200)*n^2 - (326223749821/4476780)*n + 17722 for n>9.