[go: up one dir, main page]

login
A268240
Pascal's tetrahedron of trinomial coefficients (A046816) read mod 2.
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
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
KEYWORD
nonn,tabf
AUTHOR
STATUS
approved