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A132898 Triangle read by rows: T(n,k) = (-1)^(n-1)*n + (-1)^(k-1)*k - 1, 1 <= k <= n. 2
1, -2, -5, 3, 0, 5, -4, -7, -2, -9, 5, 2, 7, 0, 9, -6, -9, -4, -11, -2, -13, 7, 4, 9, 2, 11, 0, 13, -8, -11, -6, -13, -4, -15, -2, -17, 9, 6, 11, 4, 13, 2, 15, 0, 17, -10, -13, -8, -15, -6, -17, -4, -19, -2, -21, 11, 8, 13, 6, 15, 4, 17, 2, 19, 0, 21 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row sums = A132899: (1, -7, 8, -22, 23, -45,...)

LINKS

Andrew Howroyd, Table of n, a(n) for n = 1..1275 (first 50 rows)

EXAMPLE

First few rows of the triangle are:

   1;

  -2,  -5;

   3,   0,  5;

  -4,  -7, -2,  -9;

   5,   2,  7,   0,  9;

  -6,  -9, -4, -11, -2, -13;

   7,   4,  9,   2, 11,   0, 13;

  -8, -11, -6, -13, -4, -15, -2, -17;

   9,   6, 11,   4, 13,   2, 15,   0, 7;

  ...

T(5,3) = 7 = S(5) + S(3) = 5 + 3 - 1.

PROG

(PARI) T(n, k) = if(k<=n, (-1)^(n-1)*n + (-1)^(k-1)*k - 1, 0); \\ Andrew Howroyd, Sep 01 2018

CROSSREFS

Row sums are A132899.

Cf. A127648.

Sequence in context: A160127 A011035 A102892 * A265318 A279536 A269954

Adjacent sequences:  A132895 A132896 A132897 * A132899 A132900 A132901

KEYWORD

tabl,sign

AUTHOR

Gary W. Adamson, Sep 03 2007

EXTENSIONS

Name clarified and terms a(56) and beyond from Andrew Howroyd, Sep 01 2018

STATUS

approved

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Last modified May 23 05:03 EDT 2019. Contains 323508 sequences. (Running on oeis4.)