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A140574 Signed Pascal triangle with central coefficients set to zero. 1
0, -1, 1, -1, 0, -1, -1, 0, 0, 1, -1, 4, 0, 4, -1, -1, 5, 0, 0, -5, 1, -1, 6, -15, 0, -15, 6, -1, -1, 7, -21, 0, 0, 21, -7, 1, -1, 8, -28, 56, 0, 56, -28, 8, -1, -1, 9, -36, 84, 0, 0, -84, 36, -9, 1, -1, 10, -45, 120, -210, 0, -210, 120, -45, 10, -1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
0,12
COMMENTS
Row sums are 0, 0, -2, 0, 6, 0, -20, 0, 70, 0, -252, ...
LINKS
FORMULA
t(n,m) = (-1)^(m+1)*binomial(n,m) if n=1 or abs(m-n/2)>=1, otherwise t(n,m)=0.
EXAMPLE
0;
-1, 1;
-1, 0, -1;
-1, 0, 0, 1;
-1, 4, 0, 4, -1;
-1, 5, 0, 0, -5,1;
-1, 6, -15, 0, -15, 6, -1;
-1, 7, -21, 0, 0, 21, -7, 1;
-1, 8, -28, 56, 0,56, -28, 8, -1;
-1, 9, -36, 84, 0, 0, -84, 36, -9, 1;
-1, 10, -45, 120, -210, 0, -210, 120, -45, 10, -1;
MAPLE
A140574 := proc(n, k)
if abs(k-n/2) < 1 and not n= 1 then
0;
else
(-1)^(k+1)*binomial(n, k) ;
end if;
end proc:
seq(seq(A140574(n, m), m=0..n), n=0..14) ; # R. J. Mathar, Nov 10 2011
MATHEMATICA
Clear[p, f, x, n] f[x_, n_] := (-1)^ Floor[n/2]*If [Mod[n, 2] == 1, Binomial[n, Floor[n/2]]*x^( Floor[n/2]) - Binomial[n, Floor[n/2] + 1]*x^(Floor[n/2] + 1), Binomial[n, Floor[n/2]]*x^(Floor[n/2])]; p[x, 0] = 0; p[x, 1] = 1 - x; p[x_, n_] := p[x, n] = f[x, n] - (1 - x)^n; Table[CoefficientList[p[x, n], x], {n, 0, 10}]; Flatten[%]
CROSSREFS
Sequence in context: A123583 A236112 A226787 * A010636 A222302 A222617
KEYWORD
tabl,less,sign
AUTHOR
EXTENSIONS
Adapted offset and terms to the example. - R. J. Mathar, Nov 10 2011
STATUS
approved

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Last modified March 19 09:40 EDT 2024. Contains 370981 sequences. (Running on oeis4.)