A323971 Number of 7 X n integer matrices (m_{i,j}) such that m_{1,1}=0, m_{7,n}=2, and all rows, columns, and falling diagonals are (weakly) monotonic without jumps of 2.

1, 15, 155, 1332, 8342, 41586, 174844, 642815, 2117690, 6362806, 17671203, 45844681, 112047610, 259796057, 574776968, 1219349012, 2490738686, 4916477305, 9406990883, 17494038498, 31695618318, 56063910644, 96993880940, 164397619093, 273384891666, 446635565576

Offset

0,2

Links

Alois P. Heinz, Table of n, a(n) for n = 0..10000

Formula

G.f.: -(5*x^15 -69*x^14 +443*x^13 -1750*x^12 +4744*x^11 -9317*x^10 +13630*x^9 -15026*x^8 +12430*x^7-7561*x^6 +3263*x^5-823*x^4 +127*x^3 +35*x^2+1) / (x-1)^15.

Crossrefs

Row (or column) 7 of array in A323846.

Sequence in context: A157380 A098685 A223995 * A006096 A346843 A341918

Adjacent sequences: A323968 A323969 A323970 * A323972 A323973 A323974

Keyword

nonn,easy

Author

Alois P. Heinz, Feb 09 2019

Status

approved