OFFSET
0,12
LINKS
Alois P. Heinz, Rows n = 0..200, flattened
FORMULA
EXAMPLE
T(7,0) = 1: {}.
T(7,1) = 2: {1}, {4}.
T(7,2) = 4: {1,3}, {2,7}, {3,6}, {4,5}.
T(7,3) = 5: {1,2,6}, {1,3,5}, {2,3,4}, {3,6,7}, {4,5,7}.
T(7,4) = 5: {1,2,6,7}, {1,3,5,7}, {1,4,5,6}, {2,3,4,7}, {2,3,5,6}.
T(7,5) = 2: {1,2,3,4,6}, {3,4,5,6,7}.
T(7,6) = 1: {1,2,4,5,6,7}.
T(7,7) = 0.
T(8,8) = 1: {1,2,3,4,5,6,7,8}.
Triangle T(n,k) begins:
1;
1, 1;
1, 1, 0;
1, 1, 1, 0;
1, 2, 1, 1, 0;
1, 2, 2, 2, 0, 0;
1, 2, 3, 3, 2, 1, 0;
1, 2, 4, 5, 5, 2, 1, 0;
1, 2, 5, 8, 8, 6, 3, 0, 1;
1, 3, 6, 11, 14, 13, 7, 4, 1, 0;
1, 3, 7, 15, 23, 24, 19, 10, 3, 1, 0;
1, 3, 8, 20, 34, 43, 39, 25, 13, 3, 1, 0;
1, 3, 9, 26, 49, 71, 74, 60, 34, 14, 5, 0, 0;
...
MAPLE
b:= proc(n, s) option remember; expand(`if`(n=0,
`if`(issqr(s), 1, 0), b(n-1, s)+x*b(n-1, s+n)))
end:
T:= n-> (p-> seq(coeff(p, x, i), i=0..n))(b(n, 0)):
seq(T(n), n=0..16);
MATHEMATICA
b[n_, s_] := b[n, s] = Expand[If[n == 0, If[IntegerQ @ Sqrt[s], 1, 0], b[n - 1, s] + x*b[n - 1, s + n]]];
T[n_] := Function[p, Table[Coefficient[p, x, i], {i, 0, n}]][b[n, 0]];
Table[T[n], {n, 0, 10}] // Flatten (* Jean-François Alcover, Jun 03 2018, from Maple *)
CROSSREFS
Columns k=0-10 give: A000012, A000196, A176615, A281706, A281864, A281865, A281866, A281867, A281868, A281869, A281870.
Main diagonal is characteristic function of A001108.
Diagonals T(n+k,n) for k=2-10 give: A281965, A281966, A281967, A281968, A281969, A281970, A281971, A281972, A281973.
Row sums give A126024.
T(2n,n) gives A281872.
KEYWORD
nonn,tabl
AUTHOR
Alois P. Heinz, Jan 31 2017
STATUS
approved