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A135356
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Triangle T(n,k) read by rows: coefficients in the recurrence of sequences which equal their n-th differences.
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13
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2, 2, 0, 3, -3, 2, 4, -6, 4, 0, 5, -10, 10, -5, 2, 6, -15, 20, -15, 6, 0, 7, -21, 35, -35, 21, -7, 2, 8, -28, 56, -70, 56, -28, 8, 0, 9, -36, 84, -126, 126, -84, 36, -9, 2, 10, -45, 120, -210, 252, -210, 120, -45, 10, 0, 11, -55, 165, -330, 462, -462, 330, -165, 55, -11, 2
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OFFSET
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1,1
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COMMENTS
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Sequences which equal their p-th differences obey recurrences a(n) = Sum_{s=1..p} T(p,s)*a(n-s).
This defines T(p,s) as essentially a signed version of a chopped Pascal triangle A014410, see A130785.
For cases like p=2, 4, 6, 8, 10, 12, 14, the denominator of the rational generating function of a(n) contains a factor 1-x; depending on the first terms in the sequences a(n), additional, simpler recurrences may exist if this cancels with a factor in the numerator. - R. J. Mathar, Jun 10 2008
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LINKS
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FORMULA
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T(n,k) = (-1)^(k+1)*A007318(n, k). T(n,n) = 1 - (-1)^n.
Sum_{k=1..n} T(n, k) = 2.
Sum_{k=1..n} (-1)^(k-1)*T(n, k) = 2*A051049(n-1).
Sum_{k=1..n-1} T(n, k) = (1 + (-1)^n).
Sum_{k=1..n-1} (-1)^(k-1)*T(n, k) = A000225(n-1).
T(2*n, n) = (-1)^(n-1)*A000984(n), n >= 1. (End)
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EXAMPLE
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Triangle begins with row n=1:
2;
2, 0;
3, -3, 2;
4, -6, 4, 0;
5, -10, 10, -5, 2;
6, -15, 20, -15, 6, 0;
7, -21, 35, -35, 21, -7, 2;
8, -28, 56, -70, 56, -28, 8, 0;
9, -36, 84, -126, 126, -84, 36, -9, 2;
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MAPLE
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T:= (p, s)-> `if`(p=s, 2*irem(p, 2), (-1)^(s+1) *binomial(p, s)):
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MATHEMATICA
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T[p_, s_]:= If[p==s, 2*Mod[s, 2], (-1)^(s+1)*Binomial[p, s]];
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PROG
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(Magma)
A135356:= func< n, k | k eq n select 1-(-1)^n else (-1)^(k+1)*Binomial(n, k) >;
(SageMath)
if (k==n): return 2*(n%2)
else: return (-1)^(k+1)*binomial(n, k)
flatten([[A135356(n, k) for k in range(1, n+1)] for n in range(1, 13)]) # G. C. Greubel, Apr 09 2023
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CROSSREFS
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Related sequences: A000079 (n=1), A131577 (n=2), (A131708 , A130785, A131562, A057079) (n=3), (A000749, A038503, A009545, A038505) (n=4), A133476 (n=5), A140343 (n=6), A140342 (n=7).
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KEYWORD
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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