A078996 - OEIS

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A078996

Triangle read by rows: let f(x) = x/(1-x-x^2); n-th row gives coefficients of denominator polynomial of n-th derivative f(x)^(n), with highest powers first, for n >= 0.

-1, -1, 1, 1, 2, -1, -2, 1, 1, 3, 0, -5, 0, 3, -1, 1, 4, 2, -8, -5, 8, 2, -4, 1, 1, 5, 5, -10, -15, 11, 15, -10, -5, 5, -1, 1, 6, 9, -10, -30, 6, 41, -6, -30, 10, 9, -6, 1, 1, 7, 14, -7, -49, -14, 77, 29, -77, -14, 49, -7, -14, 7, -1, 1, 8, 20, 0, -70, -56, 112, 120, -125, -120, 112, 56, -70, 0, 20, -8, 1

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

OFFSET

0,5

LINKS

Table of n, a(n) for n=0..79.

FORMULA

f(x)^(n), for n=0, 1, 2, 3, 4, ..., where f(x)= x/(1-x-x^2).

G.f.: G(0)/(2*x) - 1/x - 2 - 2*x + 2*x^2 , where G(k)= 1 + 1/( 1 - (1+x-x^2)*x^(2*k+1)/((1+x-x^2)*x^(2*k+1) + 1/G(k+1) )); (continued fraction). - Sergei N. Gladkovskii, Jul 06 2013

EXAMPLE

Triangle begins:

-1, -1, 1;

1, 2, -1, -2, 1;

1, 3, 0, -5, 0, 3, -1;

...

CROSSREFS

See A084610 for another version of this triangle.

Sequence in context: A090001 A269329 A117166 * A084610 A303336 A361462

Adjacent sequences: A078993 A078994 A078995 * A078997 A078998 A078999

KEYWORD

sign,tabf

AUTHOR

Mohammad K. Azarian, Jan 12 2003

EXTENSIONS

Edited by N. J. A. Sloane, Jan 15 2011

STATUS

approved