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A068344 Square array read by antidiagonals of T(n,k) = sign(n-k). 0
0, -1, 1, -1, 0, 1, -1, -1, 1, 1, -1, -1, 0, 1, 1, -1, -1, -1, 1, 1, 1, -1, -1, -1, 0, 1, 1, 1, -1, -1, -1, -1, 1, 1, 1, 1, -1, -1, -1, -1, 0, 1, 1, 1, 1, -1, -1, -1, -1, -1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, 0, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, 0, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1, -1, -1, 1, 1, 1, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..101.

FORMULA

a(n) = sign(A002260(n) - A004736(n)) or a(n) = sign((n-t(t+1)/2) - (t*t+3*t+4)/2-n)) where t = floor((-1+sqrt(8*n-7))/2).  - Boris Putievskiy, Dec 24 2012

EXAMPLE

The start of the array is:

0;

-1,...1;

-1,...0,...1;

-1,..-1,...1,...1;

-1,..-1,...0,...1,...1;

. . .

- Boris Putievskiy, Dec 24 2012

CROSSREFS

Cf. A049581, A057427, A057428, A002260, A004736. As a straight sequence, a(n)=0 when n is in A046092. A023532 seen as a triangle is half this square.

Sequence in context: A285596 A257680 A323377 * A161382 A138886 A269528

Adjacent sequences:  A068341 A068342 A068343 * A068345 A068346 A068347

KEYWORD

easy,sign,tabl

AUTHOR

Henry Bottomley, Mar 06 2002

STATUS

approved

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Last modified December 15 22:02 EST 2019. Contains 330012 sequences. (Running on oeis4.)