%I A008293
%S A008293 1,1,1,1,2,2,2,8,6,16,40,24,16,136,240,120,272,1232,1680,720,272,3968,
%T A008293 12096,13440,5040,7936,56320,129024,120960,40320,7936,176896,814080,
%U A008293 1491840,1209600,362880,353792,3610112,12207360,18627840,13305600
%N A008293 Triangle of coefficients in expansion of D^n (tan x) in powers of tan 
               x.
%D A008293 Haigh, Gordon; A "natural" approach to Pick's theorem. Math. Gaz. 64 
               (1980), no. 429, 173-180.
%D A008293 Knuth, D. E. and Buckholtz, Thomas J., Computation of tangent, Euler 
               and Bernoulli numbers. Math. Comp. 21 1967 663-688.
%H A008293 M.-P. Grosset and A. P. Veselov, <a href="http://arXiv.org/abs/math.GM/
               0503175">Bernoulli numbers and solitons</a>
%F A008293 a(0, k)=delta(1, k); a(n+1, k)=(k-1)a(n, k-1)+(k+1)a(n, k+1).
%Y A008293 Cf. A008294. Other versions of same triangle: A101343, A155100.
%Y A008293 Sequence in context: A011202 A085484 A116585 this_sequence A011140 A068718 
               A075097
%Y A008293 Adjacent sequences: A008290 A008291 A008292 this_sequence A008294 A008295 
               A008296
%K A008293 nonn,tabl,easy,nice
%O A008293 0,5
%A A008293 N. J. A. Sloane (njas(AT)research.att.com).