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A281587 Triangle read by rows, e.g.f. exp(x*z)*(2*(exp(z)+1)/(cosh(z)+cos(z))-1).

%I A281587 #5 Feb 01 2017 13:44:41
%S A281587 1,1,1,1,2,1,1,3,3,1,-1,4,6,4,1,-4,-5,10,10,5,1,-14,-24,-15,20,15,6,1,
%T A281587 -34,-98,-84,-35,35,21,7,1,69,-272,-392,-224,-70,56,28,8,1,496,621,
%U A281587 -1224,-1176,-504,-126,84,36,9,1,2896,4960,3105,-4080,-2940,-1008,-210,120,45,10,1
%N A281587 Triangle read by rows, e.g.f. exp(x*z)*(2*(exp(z)+1)/(cosh(z)+cos(z))-1).
%e A281587 Triangle starts:
%e A281587 [   1]
%e A281587 [   1,   1]
%e A281587 [   1,   2,   1]
%e A281587 [   1,   3,   3,   1]
%e A281587 [  -1,   4,   6,   4,  1]
%e A281587 [  -4,  -5,  10,  10,  5,  1]
%e A281587 [ -14, -24, -15,  20, 15,  6, 1]
%e A281587 [ -34, -98, -84, -35, 35, 21, 7, 1]
%p A281587 A281587_row := proc(n) exp(x*z)*(2*(exp(z)+1)/(cosh(z)+cos(z))-1);
%p A281587 n!*coeff(series(%,z,n+1),z,n); PolynomialTools:-CoefficientList(%,x) end:
%p A281587 for n from 0 to 12 do A281587_row(n) od;
%Y A281587 Cf. A130595 (m=1), A109449 (m=2), A215064 (m=3), A281587 (m=4).
%Y A281587 Cf. A178964 (col. 0), A281588 (col. 1).
%K A281587 sign,tabl
%O A281587 0,5
%A A281587 _Peter Luschny_, Feb 01 2017