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A140218 Denominators of the inverse triangle to that described in A133135. 2
1, 1, 1, 1, 2, 1, 1, 2, 1, 1, 1, 4, 1, 2, 1, 1, 4, 1, 2, 1, 1, 1, 4, 1, 1, 1, 2, 1, 1, 4, 1, 1, 1, 2, 1, 1, 1, 8, 1, 2, 1, 4, 1, 2, 1, 1, 8, 1, 2, 1, 4, 1, 2, 1, 1, 1, 8, 1, 1, 1, 4, 1, 2, 1, 2, 1, 1, 8, 1, 1, 1, 4, 1, 2, 1, 2, 1, 1, 1, 8, 1, 2, 1, 2, 1, 2, 1, 4, 1, 2, 1, 1, 8, 1, 2, 1, 2, 1, 2, 1, 4, 1, 2, 1, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,5

COMMENTS

The inverse of the triangle of fractions starts

1;

-1, 1;

1, -3/2, 1;

-1, 3/2,-2, 1;

1, -5/4, 2, -5/2, 1;

-1, 5/4 -1, 5/2, -3, 1;

1, -7/4, 1, 0, 3, -7/2, 1;

-1, 7/4,-4, 0, 2, 7/2,-4, 1;

1, 3/8, 4,-21/2, -2, 21/4, 4,-9/2, 1;

-1, -3/8,13, 21/2,-26,-21/4,10, 9/2,-5, 1;

to yield the triangle of denominators

1;

1,1;

1,2,1;

1,2,1,1;

1,4,1,2,1;

1,4,1,2,1,1;

1,4,1,1,1,2,1;

1,4,1,1,1,2,1,1;

1,8,1,2,1,4,1,2,1;

1,8,1,2,1,4,1,2,1,1;

1,8,1,1,1,4,1,2,1,2,1;

1,8,1,1,1,4,1,2,1,2,1,1;

Number pairs show up if reading this along diagonals or columns.

LINKS

Table of n, a(n) for n=0..104.

CROSSREFS

Cf. A133135, A140216, A000079.

Sequence in context: A117975 A143258 A027199 * A193805 A159704 A101428

Adjacent sequences:  A140215 A140216 A140217 * A140219 A140220 A140221

KEYWORD

nonn,frac,tabl

AUTHOR

Paul Curtz, Jun 22 2008

EXTENSIONS

Extended by R. J. Mathar, Aug 02 2008

STATUS

approved

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Last modified April 17 11:48 EDT 2021. Contains 343064 sequences. (Running on oeis4.)