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A130266 A051340 * A128174. 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 (list; table; graph; refs; listen; history; text; internal format)
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 are:

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: A257164 A190555 A141843 * A261595 A211197 A258246

Adjacent sequences:  A130263 A130264 A130265 * A130267 A130268 A130269

KEYWORD

nonn,tabl,easy

AUTHOR

Gary W. Adamson, May 18 2007

STATUS

approved

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Last modified September 23 05:43 EDT 2018. Contains 315273 sequences. (Running on oeis4.)