A143987 - OEIS

A143987

Eigentriangle of (A007318)^(-1); row sums = A014182, exp(1-x-exp(-x)).

1, -1, 1, 1, 2, 0, -1, 3, 0, -1, 1, -4, 0, 4, 1, -1, 5, 0, -10, -5, 2, 1, -6, 0, 20, 15, -12, -9, -1, 7, 0, -35, -35, 42, 63, 9, 1, -8, 0, 56, 70, -112, -252, -72, 50, -1, 9, 0, -84, -126, 252, 756, 324, -450, -267, 1, -10, 0, 120, 210, -504, -1890, -1080, 2250, 2670, 413

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OFFSET

0,5

COMMENTS

Sum of n-th row terms = rightmost term of next row. Row sums = A014182: (1, 0, -1, 1, 2, -9, 9, 50, -267,...).

Right border = A014182 shifted: (1, 1, 0, -1, 1, 2, -9,...).

LINKS

Table of n, a(n) for n=0..65.

FORMULA

(A007318^(-1) * (A014182 * 0^(n-k))) 0<=k<=n

A007318^(-1) = the inverse of Pascal's triangle.

Given A014182: (1, 0, -1, 1, 2, -9, 9,...) = expansion of exp(1-x-exp(-x)), we preface A014182 with a "1" getting (1, 1, 0, -1, 1, 2, -9,...).

Then diagonalize it as an infinite lower triangular matrix R =

0, 1;

0, 0, 0;

0, 0, 0, -1;

0, 0, 0, 0, 1;

...

Finally, take the inverse binomial transform of triangle R, getting A143987.

Given the inverse of Pascal's triangle by rows, we apply termwise products of equal numbers of terms in the sequence: (1, 1, 0, -1, 1, 2, -9, 9,...).

EXAMPLE

First few rows of the triangle =

-1, 1;

1, -2, 0;

-1, 3, 0, -1;

1, -4, 0, 4, 1;

-1, 5, 0, -10, -5, 2;

1, -6, 0, 20, 15, -12, -9;

-1, 7, 0, -35, -35, 42, 63, 9;

1, -8, 0, 56, 70, -112, -252, 72, 50;

...

Example: row 4 = (1, -4, 0, 4, 1) = termwise products of (1, -4, 6, -4, 1) and (1, 1, 0, -1, 1).= (1*1, -4*1, 6*0, -4*-1, 1*1).

CROSSREFS

Cf. A007318, A014182.

Sequence in context: A129503 A225682 A144185 * A309013 A112760 A096087

Adjacent sequences: A143984 A143985 A143986 * A143988 A143989 A143990

KEYWORD

tabl,sign

AUTHOR

Gary W. Adamson, Sep 07 2008

STATUS

approved