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Triangle read by rows, application of the transformation A337966 to Euler's triangle A173018. T(n, k) for 0 <= k <= n.
4

%I #14 Oct 06 2020 07:02:06

%S 1,1,0,-1,-1,0,0,-4,0,0,-1,11,11,-1,0,-1,0,66,0,-1,0,1,57,-302,-302,

%T 57,1,0,0,120,0,-2416,0,120,0,0,1,-247,-4293,15619,15619,-4293,-247,1,

%U 0,1,0,-14608,0,156190,0,-14608,0,1,0,-1,-1013,47840,455192,-1310354,-1310354,455192,47840,-1013,-1,0

%N Triangle read by rows, application of the transformation A337966 to Euler's triangle A173018. T(n, k) for 0 <= k <= n.

%C Row sums divided by 2^floor(n/2) are the Euler up/down numbers A000111 with signs.

%F T(n, k) = A173018(n, k)*A337966(n, k).

%e Triangle starts:

%e [0] 1

%e [1] 1, 0

%e [2] -1, -1, 0

%e [3] 0, -4, 0, 0

%e [4] -1, 11, 11, -1, 0

%e [5] -1, 0, 66, 0, -1, 0

%e [6] 1, 57, -302, -302, 57, 1, 0

%e [7] 0, 120, 0, -2416, 0, 120, 0, 0

%e [8] 1, -247, -4293, 15619, 15619, -4293, -247, 1, 0

%e [9] 1, 0, -14608, 0, 156190, 0, -14608, 0, 1, 0

%e .

%e A000111(4) = 5 = -1 + 11 + 11 - 1 = 20/4 = A001250(4)/2.

%e A000111(5) = 16 = -1 + 66 - 1 = 64/4 = A001250(5)/2.

%p U := (n, k) -> combinat:-eulerian1(n, k):

%p Trow := n -> seq(coeff(A337966(n, x, U), z, k), k=0..n):

%p seq(lprint([n], Trow(n)), n=0..9);

%Y Cf. A337966, A173018, A000111, A001250, A337616 (row sums).

%K sign,tabl

%O 0,8

%A _Peter Luschny_, Oct 04 2020