A219879 Number of nX4 arrays of the minimum value of corresponding elements and their horizontal, diagonal or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 nX4 array.
10, 17, 129, 621, 2645, 10350, 40239, 155199, 581728, 2085519, 7121374, 23225035, 72683520, 219218974, 639377404, 1808073511, 4967931875, 13286469360, 34640551307, 88162618939, 219292820124, 533661457600, 1271821824645
Offset: 1
Keywords
Examples
Some solutions for n=3 ..1..0..0..0....0..0..0..0....2..0..0..0....1..1..0..1....2..1..1..1 ..1..0..0..0....0..0..0..0....2..0..0..0....1..0..0..0....2..1..1..1 ..1..1..0..0....1..1..0..1....2..2..0..2....1..0..0..0....2..2..1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = (1/1105220249217462744317952000000)*n^29 + (1/38111043076464232562688000000)*n^28 - (1/201645730563302817792000000)*n^27 + (389/604937191689908453376000000)*n^26 - (307/46533630129992957952000000)*n^25 - (773/404640261999938764800000)*n^24 + (40878821/195441246545970423398400000)*n^23 - (70069501/8497445501998714060800000)*n^22 + (12139/477733485241958400000)*n^21 + (50109247/2829652181817753600000)*n^20 - (445566582679/404640261999938764800000)*n^19 + (737417025883/21296855894733619200000)*n^18 - (2216933583028729/5814041659262278041600000)*n^17 - (6268242075250621/342002450544839884800000)*n^16 + (18619463335254179/16285830978325708800000)*n^15 - (536852810288080877/16285830978325708800000)*n^14 + (1152350125136381123/2129685589473361920000)*n^13 - (24885562289413355029/10648427947366809600000)*n^12 - (39408208806540972298007/289685642113592524800000)*n^11 + (1255759711529881816639841/289685642113592524800000)*n^10 - (4460229918485515193847251/63225040937490432000000)*n^9 + (370772167856232917329483/540384965277696000000)*n^8 - (39409170362295331975190999/13464592051502592000000)*n^7 - (280106596148918041437854963/13464592051502592000000)*n^6 + (23189350672718808866722526453/51053244861947328000000)*n^5 - (379821968293133120568499603/102106489723894656000)*n^4 + (3496996713409130344932041/202592241515664000)*n^3 - (3708578246594560887479/83889126921600)*n^2 + (35941859372224430069/776363187600)*n + 10128532 for n>12
Comments