A224022 Number of nX6 0..3 arrays with rows nondecreasing and antidiagonals unimodal

84, 7056, 387729, 16861106, 646270418, 23151623729, 800511624819, 27185446777503, 915085673227317, 30672939766468469, 1026121422083211534, 34296931507964424065, 1145877902919763472821, 38277578417660461200345

Offset

1,1

Comments

Column 6 of A224024

Links

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

Formula

Empirical: a(n) = 84*a(n-1) -2771*a(n-2) +49004*a(n-3) -526214*a(n-4) +3641009*a(n-5) -16632719*a(n-6) +48536326*a(n-7) -53423733*a(n-8) -313959977*a(n-9) +1729942603*a(n-10) -7086418537*a(n-11) +13780962535*a(n-12) +5231265096*a(n-13) -20279410782*a(n-14) +609579098232*a(n-15) +294855159788*a(n-16) +2331852968592*a(n-17) +7276333185488*a(n-18) +4826951354776*a(n-19) +18771064269632*a(n-20) +25683656373760*a(n-21) +16941876341184*a(n-22) +25615354625280*a(n-23) +22113238049280*a(n-24) +5504163840000*a(n-25)

Example

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

Crossrefs

Sequence in context: A223869 A224389 A223991 * A283947 A265586 A278725

Adjacent sequences: A224019 A224020 A224021 * A224023 A224024 A224025

Keyword

nonn

Author

R. H. Hardin Mar 30 2013

Status

approved