A219597 Number of 4Xn arrays of the minimum value of corresponding elements and their horizontal or vertical neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 4Xn array.
10, 46, 264, 1114, 4152, 14793, 51122, 170728, 550156, 1714425, 5181670, 15217623, 43453991, 120646669, 325663378, 854806408, 2182941966, 5428211529, 13157408701, 31124038143, 71939605189, 162674579688, 360302418944
Offset: 1
Keywords
Examples
Some solutions for n=3 ..0..0..0....0..0..0....1..0..0....0..0..0....1..0..0....0..0..0....0..0..0 ..0..0..0....1..0..0....1..0..0....1..0..0....0..0..0....2..0..0....1..0..0 ..0..0..0....0..0..0....1..1..0....1..1..0....2..0..0....2..1..0....1..0..0 ..1..1..0....0..0..0....1..1..2....1..2..2....2..2..1....2..1..1....1..1..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..143
Formula
Empirical: a(n) = (1/32315020923606220800000)*n^25 - (109/11079435745236418560000)*n^24 + (2143/1292600836944248832000)*n^23 - (79003/421500272916602880000)*n^22 + (50173/3193183885731840000)*n^21 - (44960737/43792236147179520000)*n^20 + (27515689/510909421717094400)*n^19 - (60384781/26191528796160000)*n^18 + (21813448039/268899695640576000)*n^17 - (2221068910103/949057749319680000)*n^16 + (9482825036023/173993920708608000)*n^15 - (91557547148539/93211028951040000)*n^14 + (5251971236010727/434984801771520000)*n^13 - (62481716542887379/1491376463216640000)*n^12 - (9282784846386031/3954407288832000)*n^11 + (4293029543793101017/59316109332480000)*n^10 - (105931313393469849253/84031154887680000)*n^9 + (202993929290792591407/13095764398080000)*n^8 - (3712306914099958615759/26609865714432000)*n^7 + (11336104215245400553903/12671364625920000)*n^6 - (369076146776783247776693/101634903770400000)*n^5 + (41196192835097343490679/9034213668480000)*n^4 + (15522433799255326230017/346311523958400)*n^3 - (23040269972514059058427/74209612276800)*n^2 + (112252070661045629/127481640)*n - 1011429662 for n>12
Comments