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A090171
Triangle read by rows, related to Pascal's triangle read mod 2, starting with 0, 1, 0.
5
0, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0
OFFSET
0,1
LINKS
Y. Moshe, The density of 0's in recurrence double sequences, J. Number Theory, 103 (2003), 109-121; see Fig. 2.
FORMULA
T(n, k) = T(n-1, k) + T(n-1, k-1) + T(n-2, k) + T(n-2, k-1) + T(n-2, k-2) for n >= 2, k >= 0, with initial conditions specified by first two rows.
EXAMPLE
Triangle begins:
0
1 0
1 1 0
0 1 0 0
1 1 1 1 0
...
CROSSREFS
Cf. A090172, A090173, A090174, A091533, A091562, A205575 (same recurrence).
a(n, k) = A090174(n-1, k), k<n, 0 otherwise.
Sequence in context: A327183 A347870 A188967 * A316832 A086747 A188973
KEYWORD
nonn,easy,tabl
AUTHOR
N. J. A. Sloane, Jan 19 2004
EXTENSIONS
Edited and extended by Christian G. Bower, Jan 20 2004
STATUS
approved