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A372345
Square array A(n, k), n, k >= 0, read by upwards antidiagonals; for any n, k >= 0 with respective binary expansions Sum_{i >= 0} b_i * 2^i and Sum_{i >= 0} c_i * 2^i, A(n, k) = Sum_{i >= 0} (b_{i+1} * c_i + b_i * c_{i+1}) * 3^i.
2
0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 3, 2, 3, 0, 0, 0, 1, 4, 3, 3, 4, 1, 0, 0, 1, 3, 4, 0, 4, 3, 1, 0, 0, 0, 4, 4, 0, 0, 4, 4, 0, 0, 0, 0, 0, 5, 3, 0, 3, 5, 0, 0, 0, 0, 1, 1, 0, 3, 4, 4, 3, 0, 1, 1, 0, 0, 1, 0, 1, 9, 4, 6, 4, 9, 1, 0, 1, 0
OFFSET
0,24
COMMENTS
The digits in the ternary expansion of A(n, k) correspond to permanents of 2 X 2 matrices made up of binary digits of n and k.
FORMULA
A(k, n) = A(n, k).
EXAMPLE
Array A(n, k) begins:
n\k | 0 1 2 3 4 5 6 7 8 9 10
----+--------------------------------------
0 | 0 0 0 0 0 0 0 0 0 0 0
1 | 0 0 1 1 0 0 1 1 0 0 1
2 | 0 1 0 1 3 4 3 4 0 1 0
3 | 0 1 1 2 3 4 4 5 0 1 1
4 | 0 0 3 3 0 0 3 3 9 9 12
5 | 0 0 4 4 0 0 4 4 9 9 13
6 | 0 1 3 4 3 4 6 7 9 10 12
7 | 0 1 4 5 3 4 7 8 9 10 13
8 | 0 0 0 0 9 9 9 9 0 0 0
9 | 0 0 1 1 9 9 10 10 0 0 1
10 | 0 1 0 1 12 13 12 13 0 1 0
PROG
(PARI) A(n, k) = { my (v = 0, t = 1); while (n && k, v += (bittest(n, 1)*bittest(k, 0) + bittest(n, 0)*bittest(k, 1)) * t; n \= 2; k \= 2; t *= 3; ); return (v); }
CROSSREFS
See A372344 for a similar sequence.
Sequence in context: A108032 A053370 A016458 * A058513 A319650 A285736
KEYWORD
nonn,base,tabl
AUTHOR
Rémy Sigrist, Apr 28 2024
STATUS
approved