OFFSET
0,6
LINKS
Alois P. Heinz, Antidiagonals n = 0..34, flattened
EXAMPLE
Square array A(n,k) begins:
: 1, 1, 1, 1, 1, 1, 1, ...
: 1, 1, 1, 1, 1, 1, 1, ...
: 2, 2, 2, 2, 2, 2, 2, ...
: 4, 5, 4, 4, 4, 4, 4, ...
: 8, 15, 8, 8, 8, 8, 8, ...
: 16, 52, 18, 16, 16, 16, 16, ...
: 32, 203, 40, 32, 32, 32, 32, ...
: 64, 877, 101, 68, 64, 64, 64, ...
: 128, 4140, 254, 144, 128, 128, 128, ...
: 256, 21147, 723, 304, 264, 256, 256, ...
: 512, 115975, 2064, 692, 544, 512, 512, ...
MAPLE
b:= proc(l, k, i, t) option remember; `if`(l=[], 1, add(`if`(l[j]=t,
b(subsop(j=[][], l), k, j, irem(1+t, k)), 0), j=[1, $i..nops(l)]))
end:
A:= (n, k)-> `if`(n=0, 1, `if`(k=0, 2^(n-1), b([seq(
irem(i, k), i=2..n)], k, 1, irem(2, k)))):
seq(seq(A(n, d-n), n=0..d), d=0..15);
MATHEMATICA
b[l_, k_, i_, t_] := b[l, k, i, t] = If[l == {}, 1, Sum[If[l[[j]] == t, b[ReplacePart[l, j -> Nothing], k, j, Mod[1+t, k]], 0], {j, Prepend[ Range[i, Length[l]], 1]}]]; A[n_, k_] := If[n==0, 1, If[k==0, 2^(n-1), b[Flatten[Table[Mod[i, k], {i, 2, n}]], k, 1, Mod[2, k]]]]; Table[A[n, d - n], {d, 0, 15}, {n, 0, d}] // Flatten (* Jean-François Alcover, Feb 02 2017, translated from Maple *)
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Alois P. Heinz, Jul 09 2016
STATUS
approved