A117941 - OEIS

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A117941

Inverse of number triangle A117939.

1, -2, 1, -5, 2, 1, -2, 0, 0, 1, 4, -2, 0, -2, 1, 10, -4, -2, -5, 2, 1, -5, 0, 0, 2, 0, 0, 1, 10, -5, 0, -4, 2, 0, -2, 1, 25, -10, -5, -10, 4, 2, -5, 2, 1, -2, 0, 0, 0, 0, 0, 0, 0, 0, 1, 4, -2, 0, 0, 0, 0, 0, 0, 0, -2, 1, 10, -4, -2, 0, 0, 0, 0, 0, 0, -5, 2, 1, 4, 0, 0, -2, 0, 0, 0, 0, 0, -2, 0, 0, 1, -8, 4, 0, 4, -2, 0, 0, 0, 0, 4, -2, 0, -2, 1

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

OFFSET

0,2

COMMENTS

Row sums are A117942.

T(n, k) mod 2 = A117944(n,k).

LINKS

G. C. Greubel, Rows n = 0..50 of the triangle, flattened

EXAMPLE

Triangle begins

-2, 1;

-5, 2, 1;

-2, 0, 0, 1;

4, -2, 0, -2, 1;

10, -4, -2, -5, 2, 1;

-5, 0, 0, 2, 0, 0, 1;

10, -5, 0, -4, 2, 0, -2, 1;

25, -10, -5, -10, 4, 2, -5, 2, 1;

MATHEMATICA

M[n_, k_]:= M[n, k]= If[k>n, 0, Sum[JacobiSymbol[Binomial[n, j], 3]*JacobiSymbol[Binomial[n-j, k], 3], {j, 0, n}], 0];

m:= m= With[{q = 60}, Table[M[n, k], {n, 0, q}, {k, 0, q}]];

T[n_, k_]:= Inverse[m][[n+1, k+1]];

Table[T[n, k], {n, 0, 15}, {k, 0, n}]//Flatten (* G. C. Greubel, Oct 29 2021 *)

CROSSREFS

Cf. A117939, A117942, A117944.

Sequence in context: A006556 A108790 A355914 * A134566 A128694 A088421

Adjacent sequences: A117938 A117939 A117940 * A117942 A117943 A117944

KEYWORD

sign,tabl

AUTHOR

Paul Barry, Apr 05 2006

STATUS

approved