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A130266
1
1, 1, 2, 4, 1, 3, 2, 5, 1, 4, 7, 2, 6, 1, 5, 3, 8, 2, 7, 1, 6, 10, 3, 9, 2, 8, 1, 7, 4, 11, 3, 10, 2, 9, 1, 8, 13, 4, 12, 3, 11, 2, 10, 1, 9, 5, 14, 4, 13, 3, 12, 2, 11, 1, 10, 16, 5, 15, 4, 14, 3, 13, 2, 12, 1, 11, 6, 17, 5, 16, 4, 15, 3, 14, 2, 13
OFFSET
0,3
COMMENTS
Row sums = A014255: (1, 3, 8, 12, 21, 27, 40, ...).
Left border = A123684: (1, 1, 4, 2, 7, 3, 10, 4, ...).
FORMULA
A051340 * A128174 as infinite lower triangular matrices.
EXAMPLE
First few rows of the triangle:
1;
1, 2;
4, 1, 3;
2, 5, 1, 4;
7, 2, 6, 1, 5;
3, 8, 2, 7, 1, 6;
10, 3, 9, 2, 8, 1, 7;
...
MAPLE
A128174 := proc(n, k)
if k > n or k < 1 then
0;
else
modp(k+n+1, 2) ;
end if;
end proc:
A051340 := proc(n, k)
if k = n then
n ;
elif k <= n then
1;
else
0;
end if;
end proc:
A130266 := proc(n, k)
add( A051340(n, j)*A128174(j, k), j=k..n) ;
end proc:
seq(seq(A130266(n, k), k=1..n), n=1..15) ; # R. J. Mathar, Aug 06 2016
CROSSREFS
KEYWORD
nonn,tabl,easy
AUTHOR
Gary W. Adamson, May 18 2007
STATUS
approved