cp's OEIS Frontend

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.

A127626 Triangle T(n,k) = A018804(k) if k|n, else T(n,k)=0.

Original entry on oeis.org

1, 1, 3, 1, 0, 5, 1, 3, 0, 8, 1, 0, 0, 0, 9, 1, 3, 5, 0, 0, 15, 1, 0, 0, 0, 0, 0, 13, 1, 3, 0, 8, 0, 0, 0, 20, 1, 0, 5, 0, 0, 0, 0, 0, 21, 1, 3, 0, 0, 9, 0, 0, 0, 0, 27, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 21, 1, 3, 5, 8, 0, 15, 0, 0, 0, 0, 0, 40, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 25
Offset: 1

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Author

Gary W. Adamson, Jan 20 2007

Keywords

Comments

Inverse Mobius transform of a matrix with A018804 in the main diagonal and the rest zeros.

Examples

			First few rows of the triangle are:
1;
1, 3;
1, 0, 5;
1, 3, 0, 8;
1, 0, 0, 0, 9;
1, 3, 5, 0, 0, 15;
...
		

Crossrefs

Cf. A051731, A038040 (row sums), A018804 (diagonal).
Cf. A127093.

Programs

  • Haskell
    a127626 n k = a127626_tabl !! (n-1) !! (k-1)
    a127626_row n = a127626_tabl !! (n-1)
    a127626_tabl = map
       (map (\x -> if x == 0 then 0 else a018804 x)) a127093_tabl
    -- Reinhard Zumkeller, Jan 21 2014