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A262239 Number of (n+3)X(4+3) 0..1 arrays with each row and column divisible by 11, read as a binary number with top and left being the most significant bits. 1

%I

%S 12,31,238,1306,10747,77490,778464,4345849,31098659,251964601,

%T 2327886878

%N Number of (n+3)X(4+3) 0..1 arrays with each row and column divisible by 11, read as a binary number with top and left being the most significant bits.

%C Column 4 of A262240.

%H Michael S. Branicky, <a href="/A262239/a262239.py.txt">Python program</a>

%e Some solutions for n=5

%e ..0..0..1..0..1..1..0....0..0..1..0..1..1..0....0..0..1..0..1..1..0

%e ..0..1..0..0..0..0..1....1..1..0..0..0..1..1....1..1..1..1..0..0..1

%e ..0..1..1..0..1..1..1....0..1..1..0..1..1..1....0..1..0..0..0..0..1

%e ..0..1..1..0..1..1..1....1..0..0..0..0..1..0....1..1..1..1..0..0..1

%e ..1..1..0..0..0..1..1....1..1..0..0..0..1..1....1..1..1..1..0..0..1

%e ..0..0..0..0..0..0..0....0..1..1..0..1..1..1....0..0..1..0..1..1..0

%e ..1..0..0..0..0..1..0....0..1..0..0..0..0..1....0..0..0..0..0..0..0

%e ..1..1..0..0..0..1..1....0..0..1..0..1..1..0....0..1..0..0..0..0..1

%o (Python) # see link for faster program

%o from itertools import product

%o def a(n):

%o count = 0

%o mn, mx = min(n+3, 7), max(n+3, 7)

%o cands = [bin(m)[2:].zfill(mn) for m in range(0, 2**mn, 11)]

%o for arr in product(cands, repeat=mx):

%o vecs = ("".join(arr[i][j] for i in range(mx)) for j in range(mn))

%o if all(int(v, 2)%11 == 0 for v in vecs):

%o count += 1

%o return count

%o print([a(n) for n in range(1, 4)]) # _Michael S. Branicky_, Dec 31 2021

%Y Cf. A262240.

%K nonn,more

%O 1,1

%A _R. H. Hardin_, Sep 15 2015

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Last modified January 27 12:05 EST 2023. Contains 359840 sequences. (Running on oeis4.)