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.

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A143778 Eigentriangle of A001263, the Narayana triangle.

Original entry on oeis.org

1, 1, 1, 1, 3, 2, 1, 6, 12, 6, 1, 10, 40, 60, 25, 1, 15, 100, 300, 375, 136, 1, 21, 210, 1050, 2625, 2856, 927, 1, 18, 392, 2940, 12250, 26656, 25956, 7690, 1, 36, 672, 7056, 44100, 15993, 311472, 276840, 75913
Offset: 0

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Author

Gary W. Adamson, Aug 31 2008

Keywords

Comments

The Narayana triangle begins:
1;
1, 1;
1, 3, 1;
1, 6, 6, 1;
1, 10, 20, 10, 1;
...
An eigentriangle of T is generated by taking the termwise product of (n-1)-th row terms of triangle T (in this case the Narayana triangle A001263); and the eigensequence of T = A102812 = (1, 1, 2, 6, 25, 136, 927,...).
Sum of n-th row terms of triangle A143778 = rightmost term of (n+1)-th row.
Right border of the triangle = the eigensequence of T.
Row sums of the triangle = the eigensequence of T shifted one place to the left: (1, 2, 6, 25, 136,...)
(A102812 * 0^(n-k)) = an infinite lower triangular matrix with A102812 as the main diagonal and the rest zeros.

Examples

			Triangle begins:
1;
1, 1;
1, 3, 2;
1, 6, 12, 6;
1, 10, 40, 60, 25;
1, 15, 100, 300, 375, 136;
1, 21, 210, 1050, 2625, 2856, 927;
...
Row 3 = (1, 6, 12, 6) = (1*1, 6*1, 6*2, 1*6) = termwise product of row 3 of the Narayana triangle: (1, 6, 6, 1) and the first 4 terms of the eigensequence of the Narayana triangle = (1, 1, 2, 6).
		

Crossrefs

Formula

Triangle read by rows, A001263 * (A102812 * 0^(n-k)); 0<=k<=n
Apparently for kTom Copeland, Oct 08 2014
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