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%I #13 Nov 22 2021 02:35:34
%S 2,96,29184,22634496,32864600064,76717014122496,262665886073094144,
%T 1239981021847665770496,7719096548270543600615424,
%U 61267211781784116552580202496,603881788505747521507846892027904,7236592671961544936200760521440362496,103612803724706836868168667250308188995584
%N Generalized Euler number c(8,n).
%H D. Shanks, <a href="http://dx.doi.org/10.1090/S0025-5718-1967-0223295-5">Generalized Euler and class numbers</a>. Math. Comp. 21 (1967) 689-694.
%H D. Shanks, <a href="http://dx.doi.org/10.1090/S0025-5718-1968-0227093-9">Corrigenda to: "Generalized Euler and class numbers"</a>, Math. Comp. 22 (1968), 699.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/EulerNumber.html">Euler Number</a>.
%F a(n) = 2^(4n+5) * A000281(n).
%F a(n) = (2*n)!*[x^(2*n)](sec(8*x)*2*cos(4*x)). - _Peter Luschny_, Nov 21 2021
%p egf := sec(8*x)*2*cos(4*x): ser := series(egf, x, 24):
%p seq((2*n)!*coeff(ser, x, 2*n), n = 0..11); # _Peter Luschny_, Nov 21 2021
%Y Cf. A000281, A064073, A349267, A349264.
%K nonn,easy
%O 0,1
%A _Eric W. Weisstein_, Aug 31 2001
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