The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A347894 E.g.f.: Product_{k>=1} (1 + x^k)^tan(x). 2
 1, 0, 2, 3, 52, 110, 2690, 11676, 247952, 1434600, 37576168, 296088760, 7698854216, 78083294640, 2187100997328, 27174552638520, 806871808214016, 11698163585372736, 370098862531800000, 6300404006917434624, 208037772410558058624, 4032385785901175122560, 141272996628892396692096 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Table of n, a(n) for n=0..22. FORMULA E.g.f.: exp( tan(x) * Sum_{k>=1} x^k / (k*(1 - x^(2*k))) ). - Ilya Gutkovskiy, Sep 18 2021 E.g.f.: exp( tan(x) * Sum_{k>=1} A000593(k)*x^k/k ). - Seiichi Manyama, Sep 18 2021 PROG (PARI) N=40; x='x+O('x^N); Vec(serlaplace(prod(k=1, N, (1+x^k)^tan(x)))) (PARI) N=40; x='x+O('x^N); Vec(serlaplace(exp(tan(x)*sum(k=1, N, sigma(k>>valuation(k, 2))*x^k/k)))) CROSSREFS Cf. A000593, A265024, A335630, A347774, A347817, A347893, A347900. Sequence in context: A090508 A126716 A355648 * A362836 A371142 A337057 Adjacent sequences: A347891 A347892 A347893 * A347895 A347896 A347897 KEYWORD nonn AUTHOR Seiichi Manyama, Sep 18 2021 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified July 19 14:25 EDT 2024. Contains 374395 sequences. (Running on oeis4.)