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.

A143972 Eigentriangle by rows, A143971 * (A108300 * 0^(n-k)); 1<=k<=1.

Original entry on oeis.org

1, 4, 1, 7, 4, 5, 10, 7, 20, 16, 13, 10, 35, 64, 53, 16, 13, 50, 112, 212, 175, 19, 16, 65, 160, 371, 700, 578, 22, 19, 80, 208, 530, 1225, 2312, 1909, 25, 28, 95, 256, 689, 1750, 4046, 7636, 6305, 28, 25, 110, 304, 848, 2275, 5780, 23363, 25220, 20824
Offset: 1

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Author

Gary W. Adamson, Sep 06 2008

Keywords

Comments

Right border = A108300: (1, 1, 5, 16, 53, 175, 578,...). Row sums = (1, 5, 16, 53, 175, 578,...) = INVERT transform of (1, 4, 7, 10,...).
Sum of n-th row terms = rightmost term of next row.
Comment in A108300 states that (5, 16, 53, 175,...) is related to the numbers of hydrogen bonds in hydrocarbons.

Examples

			First few rows of the triangle =
1;
4, 1;
7, 4, 5;
10, 7, 10, 16;
13, 10, 35, 64, 53;
16, 13, 50, 112, 212, 175;
19, 16, 65, 160, 371, 700, 578;
22, 19, 80, 208, 530, 1225, 2312, 1909;
25, 22, 95, 256, 689, 1750, 4046, 7636, 6305;
... Example: row 4 = (10, 7, 20, 16) = termwise products of (10, 7, 4, 1) and (1, 1, 5, 16) = (10*1, 7*1, 4*5, 1*16), where (10, 7, 4, 1) = row 4 of triangle A143971.
		

Crossrefs

Formula

Eigentriangle by rows, A143971 * (A108300 * 0^(n-k)); 1<=k<=1
Triangle A143971 = (1; 4,1; 7,4,1; 10,7,4,1;...). A108300 * 0^(n-k) = an infinite lower triangular matrix with A108300 (1, 1, 5, 16, 53, 175, 578, 1909,...) in the main diagonal and the rest zeros. By rows, = termwise products of n-th row terms of A143971 and n terms of A108300.