A349264 Generalized Euler numbers, a(n) = n!*[x^n](sec(4*x)*(sin(4*x) + 1)).
1, 4, 16, 128, 1280, 16384, 249856, 4456448, 90767360, 2080374784, 52975108096, 1483911200768, 45344872202240, 1501108249821184, 53515555843342336, 2044143848640217088, 83285910482761809920, 3605459138582973251584, 165262072909347030040576, 7995891855149741436305408
Offset: 0
Keywords
Examples
Exponential generating functions of generalized Euler numbers in context: egf1 = sec(1*x)*(sin(x) + 1). [A000111, A000364, A000182] egf2 = sec(2*x)*(sin(x) + cos(x)). [A001586, A000281, A000464] egf3 = sec(3*x)*(sin(2*x) + cos(x)). [A007289, A000436, A000191] egf4 = sec(4*x)*(sin(4*x) + 1). [A349264, A000490, A000318] egf5 = sec(5*x)*(sin(x) + sin(3*x) + cos(2*x) + cos(4*x)). [A349265, A000187, A000320] egf6 = sec(6*x)*(sin(x) + sin(5*x) + cos(x) + cos(5*x)). [A001587, A000192, A000411] egf7 = sec(7*x)*(-sin(2*x) + sin(4*x) + sin(6*x) + cos(x) + cos(3*x) - cos(5*x)). [A349266, A064068, A064072] egf8 = sec(8*x)*2*(sin(4*x) + cos(4*x)). [A349267, A064069, A064073] egf9 = sec(9*x)*(4*sin(3*x) + 2)*cos(3*x)^2. [A349268, A064070, A064074]
Links
- Matthew House, Table of n, a(n) for n = 0..389
- William Y. C. Chen, Neil J. Y. Fan, Jeffrey Y. T. Jia, The generating function for the Dirichlet series Lm(s), Mathematics of Computation, Vol. 81, No. 278, pp. 1005-1023, April 2012.
- Ruth Lawrence and Don Zagier, Modular forms and quantum invariants of 3-manifolds, Asian J. Math. 3 (1999), no. 1, 93-107.
- D. Shanks, Generalized Euler and class numbers, Math. Comp. 21 (1967) 689-694.
- D. Shanks, Corrigendum: Generalized Euler and class numbers, Math. Comp. 22, (1968) 699.
- D. Shanks, Generalized Euler and class numbers, Math. Comp. 21 (1967), 689-694; 22 (1968), 699. [Annotated scanned copy]
Crossrefs
Programs
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Maple
sec(4*x)*(sin(4*x) + 1): series(%, x, 20): seq(n!*coeff(%, x, n), n = 0..19);
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Mathematica
m = 19; CoefficientList[Series[Sec[4*x] * (Sin[4*x] + 1), {x, 0, m}], x] * Range[0, m]! (* Amiram Eldar, Nov 20 2021 *) -
PARI
seq(n)={my(x='x + O('x^(n+1))); Vec(serlaplace((sin(4*x) + 1)/cos(4*x)))} \\ Andrew Howroyd, Nov 20 2021
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