A119305 - OEIS

A119305

Riordan array (1-4x, x(1-x)^3).

1, -4, 1, 0, -7, 1, 0, 15, -10, 1, 0, -13, 39, -13, 1, 0, 4, -80, 72, -16, 1, 0, 0, 95, -228, 114, -19, 1, 0, 0, -66, 462, -484, 165, -22, 1, 0, 0, 25, -630, 1375, -875, 225, -25, 1, 0, 0, -4, 588, -2772, 3185, -1428, 294, -28, 1, 0, 0, 0, -372, 4092, -8463, 6324, -2170, 372

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

OFFSET

0,2

COMMENTS

Inverse of number triangle binomial(4n-k, n-k), A119304. Row sums are A119306.

LINKS

Indranil Ghosh, Rows 0..101, flattened

FORMULA

Number triangle T(n,k) = (C(3k, n-k) + 4*C(3k, n-k-1))(-1)^(n-k).

EXAMPLE

Triangle begins

-4, 1;

0, -7, 1;

0, 15, -10, 1;

0, -13, 39, -13, 1;

0, 4, -80, 72, -16, 1;

0, 0, 95, -228, 114, -19, 1;

MATHEMATICA

Flatten[Table[(Binomial[3k, n-k]+4Binomial[3k, n-k-1])*(-1)^(n-k), {n, 0, 11}, {k, 0, n}]] (* Indranil Ghosh, Feb 26 2017 *)

PROG

(PARI) tabl(nn) = {for (n=0, nn, for (k=0, n, print1((binomial(3*k, n-k)+4*binomial(3*k, n-k-1))*(-1)^(n-k), ", "); ); print(); ); } \\ Indranil Ghosh, Feb 26 2017

CROSSREFS

Sequence in context: A204169 A255331 A296794 * A198215 A062175 A085659

Adjacent sequences: A119302 A119303 A119304 * A119306 A119307 A119308

KEYWORD

easy,sign,tabl

AUTHOR

Paul Barry, May 13 2006

STATUS

approved