A223846 Number of nX4 0..3 arrays with rows and columns unimodal.
130, 16900, 1006318, 32464394, 664770145, 9625018705, 106061178908, 936977517660, 6894239747078, 43487182160312, 240482752035786, 1186784550921046, 5302212479479600, 21699479504191666, 82147259258535281
Offset: 1
Keywords
Examples
Some solutions for n=3 ..0..3..1..1....0..2..1..1....0..0..2..0....1..2..3..1....1..2..1..0 ..1..2..3..1....0..2..2..2....0..1..2..2....1..2..3..3....0..2..3..0 ..0..0..3..1....0..1..1..3....0..0..3..3....0..3..2..0....0..3..2..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = (1224989653/34469355651846635520000)*n^24 + (1274345773/470036667979726848000)*n^23 + (47369757551/449600291111043072000)*n^22 + (8079231569/3005349539512320000)*n^21 + (171216531859/3434685188014080000)*n^20 + (13528480451/19081584377856000)*n^19 + (53112671431/6639498657792000)*n^18 + (49232848360313/672249239101440000)*n^17 + (53770073578979/97339256340480000)*n^16 + (16874019797699/4866962817024000)*n^15 + (517532991925673/28407170727936000)*n^14 + (605791149299131/7532204359680000)*n^13 + (1386471943577633089/4639837885562880000)*n^12 + (59161759217914897/63270516621312000)*n^11 + (155971027258109341/63270516621312000)*n^10 + (433061967586889413/79088145776640000)*n^9 + (1968650426732884217/192071211171840000)*n^8 + (51663699265372819/3201186852864000)*n^7 + (9092531376581516951/425757851430912000)*n^6 + (81675296147006711/3478413818880000)*n^5 + (15743753732731141/735818307840000)*n^4 + (225625755353/14865016320)*n^3 + (646759707782897/74209612276800)*n^2 + (8586693697/2677114440)*n + 1
Comments