A220206 Number of 3Xn arrays of the minimum value of corresponding elements and their horizontal, vertical or diagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..3 3Xn array

10, 38, 238, 956, 3294, 10762, 33804, 101396, 290268, 797260, 2114037, 5437406, 13608427, 33213956, 79197154, 184791538, 422567975, 948321570, 2091208462, 4536221049, 9688543730, 20391555264, 42323960656, 86685565242, 175300099767

Offset

1,1

Comments

Row 3 of A220204

Links

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

Formula

Empirical: a(n) = (1/403291461126605635584000000)*n^26 - (1/10340806695553990656000000)*n^25 - (1/124089680346647887872000)*n^24 + (1/817455074747351040000)*n^23 - (10039/269760174666625843200000)*n^22 - (199/143413171008307200000)*n^21 + (3959/23580434848481280000)*n^20 - (7187/1429117263544320000)*n^19 - (3063251/99286041467289600000)*n^18 + (3134525899/430239513024921600000)*n^17 - (18293331293/83517081940131840000)*n^16 + (14052701359/9279675771125760000)*n^15 + (927423920085097/10857220652217139200000)*n^14 - (71195294832587/25308206648524800000)*n^13 + (1453021031112971/41758540970065920000)*n^12 + (2941010310311/115037302947840000)*n^11 - (563880275631711089/80669908692172800000)*n^10 + (28582734418296013/271615854182400000)*n^9 - (4249867083162807899/5895108712120320000)*n^8 + (2277798744259856921/1965036237373440000)*n^7 + (412311744610887150719/22516040219904000000)*n^6 - (2333464272159792749359/24392376904896000000)*n^5 - (1203874529306099107997/1870082229375360000)*n^4 + (602265476891826109/59651745753600)*n^3 - (120139113981888058/2153403927675)*n^2 + (13189821894253/83140200)*n - 196824 for n>9

Example

Some solutions for n=3
..1..1..1....2..1..1....1..0..0....1..1..1....2..0..0....1..1..1....0..0..0
..3..1..1....3..1..1....3..0..0....2..1..1....1..0..0....2..1..1....0..0..0
..3..3..1....3..2..1....3..1..0....3..3..3....1..0..0....3..3..2....2..0..0

Crossrefs

Sequence in context: A164298 A050479 A288391 * A218081 A219823 A216591

Adjacent sequences: A220203 A220204 A220205 * A220207 A220208 A220209

Keyword

nonn

Author

R. H. Hardin Dec 07 2012

Status

approved