A130266 A051340 * A128174.

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, ...).

Links

Table of n, a(n) for n=0..75.

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

Cf. A051340, A128174, A014255, A123684.

Sequence in context: A141843 A322169 A332084 * A261595 A211197 A258246

Adjacent sequences: A130263 A130264 A130265 * A130267 A130268 A130269

Keyword

nonn,tabl,easy

Author

Gary W. Adamson, May 18 2007

Status

approved