A129994 - OEIS

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A129994

Triangle read by rows: 2*A007318 - I.

1, 2, 1, 2, 4, 1, 2, 6, 6, 1, 2, 8, 12, 8, 1, 2, 10, 20, 20, 10, 1, 2, 12, 30, 40, 30, 12, 1, 2, 14, 42, 70, 70, 42, 14, 1, 2, 16, 56, 112, 140, 112, 56, 16, 1, 2, 18, 72, 168, 252, 252, 168, 72, 18, 1

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

0,2

COMMENTS

Row sums = (1, 3, 7, 15, 31, ...).

LINKS

Table of n, a(n) for n=0..54.

FORMULA

Let Pascal's triangle A007318 = P, then this is 2*P - I, I = Identity matrix.

EXAMPLE

First few rows of the triangle are:

2, 1;