A213735 - OEIS

A213735

Triangle read by rows: row n is the expansion of x^n in terms of (x+k)!/x! for decreasing k.

1, 1, -1, 1, -3, 1, 1, -6, 7, -1, 1, -10, 25, -15, 1, 1, -15, 65, -90, 31, -1, 1, -21, 140, -350, 301, -63, 1, 1, -28, 266, -1050, 1701, -966, 127, -1, 1, -36, 462, -2646, 6951, -7770, 3025, -255, 1, 1, -45, 750, -5880, 22827, -42525, 34105, -9330, 511, -1

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OFFSET

0,5

COMMENTS

Signed version of A008278.

LINKS

Table of n, a(n) for n=0..54.

EXAMPLE

Triangle starts

1, -1,

1, -3, 1,

1, -6, 7, -1,

1, -10, 25, -15, 1,

1, -15, 65, -90, 31, -1,

...

The fourth row corresponds to the expansion

x^4 = 1 * (x + 3)! / x! - 6 * (x + 2)! / x! + 7 * (x + 1)! / x! - 1.

PROG

(Maxima) f1(p, n) := if n = 0 then [p] else [coeff(p, x ^ n), f1(p - expand(product(x + i, i, 1, n) * coeff(p, x^ n)), n - 1)$

f(n) := flatten(f1(x ^ n, n))$

CROSSREFS

Sequence in context: A339231 A133713 A008278 * A056858 A137251 A370757

Adjacent sequences: A213732 A213733 A213734 * A213736 A213737 A213738

KEYWORD

sign,tabl

AUTHOR

Douglas Boffey, Jun 18 2012

STATUS

approved