A223989 Number of 4Xn 0..3 arrays with rows unimodal and columns nondecreasing

35, 1225, 25410, 358118, 3770722, 31585056, 219861244, 1312747586, 6885325482, 32313530946, 137690265950, 539018300034, 1957451099304, 6647631120056, 21256016741041, 64364748455011, 185491652223781, 510953158157281

Offset

1,1

Comments

Row 4 of A223987

Links

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

Formula

Empirical: a(n) = (1/2906843957821440000)*n^24 + (11/242236996485120000)*n^23 + (4897/1529252690853888000)*n^22 + (2857/19308746096640000)*n^21 + (973813/198604245565440000)*n^20 + (4751599/38617492193280000)*n^19 + (31125329/12804747411456000)*n^18 + (103519301/2667655710720000)*n^17 + (2190105457/4304116776960000)*n^16 + (4631351591/836911595520000)*n^15 + (151304213363/3012881743872000)*n^14 + (22821847439/59779399680000)*n^13 + (807436276336499/331416991825920000)*n^12 + (2978829718733/228248616960000)*n^11 + (12597307863407/215205838848000)*n^10 + (15260090056063/69742632960000)*n^9 + (21685072444447303/32011868528640000)*n^8 + (72957402495727/42343741440000)*n^7 + (108238697285043737/30411275102208000)*n^6 + (24731243901001117/4223788208640000)*n^5 + (1127736066113539/150849578880000)*n^4 + (8436170802181/1173274502400)*n^3 + (193928573189123/37104806138400)*n^2 + (1070454625/535422888)*n + 1

Example

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

Crossrefs

Sequence in context: A224175 A223867 A095153 * A224387 A224020 A009979

Adjacent sequences: A223986 A223987 A223988 * A223990 A223991 A223992

Keyword

nonn

Author

R. H. Hardin Mar 30 2013

Status

approved