OFFSET
0,2
COMMENTS
This is a Riordan array.
LINKS
Alois P. Heinz, Rows n = 0..200, flattened (first 16 rows from Chai Wah Wu)
D. Baccherini, D. Merlini, R. Sprugnoli, Binary words excluding a pattern and proper Riordan arrays, Discrete Math. 307 (2007), no. 9-10, 1021--1037. MR2292531 (2008a:05003).
EXAMPLE
Array begins:
1;
2, 1;
6, 3, 1;
20, 10, 4, 1;
70, 35, 15, 5, 1;
248, 126, 56, 21, 6, 1;
894, 457, 210, 84, 28, 7, 1;
3264, 1674, 786, 330, 120, 36, 8, 1;
...
PROG
(Python)
from itertools import combinations
A246971_list = []
for n in range(10):
for k in range(n, -1, -1):
c, d0 = 0, ['0']*(n+k)
for x in combinations(range(n+k), n):
d = list(d0)
for i in x:
d[i] = '1'
if not '0100010' in ''.join(d):
c += 1
A246971_list.append(c) # Chai Wah Wu, Sep 12 2014
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
N. J. A. Sloane, Sep 11 2014
EXTENSIONS
More terms from Chai Wah Wu, Sep 12 2014
STATUS
approved