A220149 Number of nX4 arrays of the minimum value of corresponding elements and their horizontal or diagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 nX4 array.
10, 50, 254, 1174, 5410, 24684, 108169, 448881, 1761976, 6564622, 23314449, 79243936, 258638752, 812875058, 2465906695, 7234818015, 20565976895, 56733702403, 152106586332, 396892051129, 1009207780356, 2503839951948
Offset: 1
Keywords
Examples
Some solutions for n=3 ..0..0..0..0....2..2..0..0....2..1..0..1....1..0..0..1....1..1..0..1 ..2..2..0..0....2..2..2..2....2..2..0..0....2..0..0..0....1..1..0..0 ..2..2..2..2....2..2..2..2....2..2..2..2....2..2..1..0....2..2..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = (1/552610124608731372158976000000)*n^29 + (1/7622208615292846512537600000)*n^28 + (1/272221736260458804019200000)*n^27 + (1/1878686930714001408000000)*n^26 + (463/23266815064996478976000000)*n^25 + (127/372269041039943663616000)*n^24 + (97193/2443015581824630292480000)*n^23 + (1458253/2124361375499678515200000)*n^22 + (293509/55178217545446195200000)*n^21 + (1203901/1051013667532308480000)*n^20 + (19197187/20232013099996938240000)*n^19 - (215771663/10648427947366809600000)*n^18 + (47996570583761/2907020829631139020800000)*n^17 - (3130777943459/13680098021793595392000)*n^16 + (352784890291/174491046196346880000)*n^15 + (12242591085947/145409205163622400000)*n^14 - (2308802430337703/1064842794736680960000)*n^13 + (63970460933829533/2129685589473361920000)*n^12 - (7607446827742849/82297057418634240000)*n^11 - (845289139000912665797/289685642113592524800000)*n^10 + (16663286001178049022791/284512684218706944000000)*n^9 - (300232887874952342719/602143247023718400000)*n^8 + (10527514392059792417183/6059066423176166400000)*n^7 + (113898768509462767685501/13464592051502592000000)*n^6 - (19927257308688059839763/149570053306486312500)*n^5 + (32438984170527374840711/44394125966910720000)*n^4 - (955894333256214244573/455832543410244000)*n^3 + (2762815941001472611/964724959598400)*n^2 - (432088153285363/1164544781400)*n - 2315 for n>4
Comments