A268240 Pascal's tetrahedron of trinomial coefficients (A046816) read mod 2.

1, 1, 1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1

Offset

0

Comments

Might be called Sierpinski's tetrahedron, by analogy with A047999.

The number of 1's in the n-th slice is A048883(n), 3^wt(n). - N. J. A. Sloane, Feb 14 2016

Links

R. J. Mathar, Table of n, a(n) for n = 0..5455

Maple

# Pascal tetrahedron mod 2 A268240 (based on program in A046816):
A268240 := proc(i, j, k)
    modp(A046816(i, j, k), 2) ;
end proc:
seq(seq(seq(A268240(i, j, k), j=0..i), i=0..k), k=0..8);
# Another version from N. J. A. Sloane, Feb 14 2016:
MC:=(i, j, k) -> (i+j+k)!/(i!*j!*k!);
PT:=proc(n) local T, i, j, k; T:=0;
for i from n by -1 to 0 do
for j from n-i by -1 to 0 do  lprint((MC(i, j, n-i-j) mod 2)); od: od: end;
for n from 0 to 8 do lprint("n=", n);  PT(n); od:

Crossrefs

Cf. A007318, A047999, A046816, A048883.

Sequence in context: A071029 A071030 A355938 * A104037 A014044 A014079

Adjacent sequences: A268237 A268238 A268239 * A268241 A268242 A268243

Keyword

nonn,tabf

Author

Benoit Cloitre and N. J. A. Sloane, Feb 05 2016

Status

approved