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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A160182 Triangle read by rows, 1 / ((-1)*A129184 * A051731 + I), I = Identity matrix.

Original entry on oeis.org

1, 1, 1, 2, 1, 1, 3, 1, 1, 1, 5, 2, 1, 1, 1, 6, 2, 1, 1, 1, 1, 10, 4, 2, 1, 1, 1, 1, 11, 4, 2, 1, 1, 1, 1, 1, 16, 6, 3, 2, 1, 1, 1, 1, 1, 19, 7, 4, 2, 1, 1, 1, 1, 1, 1, 26, 10, 5, 3, 2, 1, 1, 1, 1, 1, 1
Offset: 1

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Author

Gary W. Adamson, May 03 2009

Keywords

Comments

Inverse mobius transform (A051731) * the triangle shifts row terms to the right deleting the right border, getting triangle A160183: (1; 2,1; 3,1,1; 5,2,1,1;...).

Examples

			First few rows of the triangle:
   1;
   1,  1;
   2,  1,  1;
   3,  1,  1,  1;
   5,  2,  1,  1,  1;
   6,  2,  1,  1,  1,  1;
  10,  4,  2,  1,  1,  1,  1;
  11,  4,  2,  1,  1,  1,  1,  1;
  16,  6,  3,  2,  1,  1,  1,  1,  1;
  19,  7,  4,  2,  1,  1,  1,  1,  1,  1;
  26, 10,  5,  3,  2,  1,  1,  1,  1,  1,  1;
  ...
		

Crossrefs

Row sums = A068336. Left border = A003238.

Programs

  • Maple
    A160182den := proc(n,k)
        a := add( A129184(n,i)*A051731(i,k),i=1..n) ;
        if n =k then
            -a+1 ;
        else
            -a;
        end if;
    end proc:
    N := 20 :
    M := Matrix(N,N) :
    for n from 1 to N do
    for k from 1 to N do
        M[n,k] := A160182den(n,k) ;
    end do:
    end do:
    MatrixInverse(M) ;  # R. J. Mathar, Aug 04 2015

Formula

Triangle read by rows, 1 / ((-1)*A129184 * A051731 + I), I = Identity matrix. The operations shift the inverse Mobius transform (A051731) down, changing the signs to (-1), then add I = (1,1,1,...) as the right border.