cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A307309 Self-composition of the Dedekind psi function (A001615).

Original entry on oeis.org

1, 6, 26, 99, 348, 1194, 4000, 13326, 44058, 144066, 462504, 1459194, 4545588, 14068554, 43450848, 134213808, 414692130, 1280610858, 3948172380, 12142365042, 37235047770, 113844652986, 347103133068, 1055610536520, 3202944247674, 9697395164616, 29298206343284
Offset: 1

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Author

Ilya Gutkovskiy, Apr 02 2019

Keywords

Crossrefs

Programs

  • Mathematica
    g[x_] := g[x] = Sum[MoebiusMu[k]^2 x^k/(1 - x^k)^2, {k, 1, 27}]; a[n_] := a[n] = SeriesCoefficient[g[g[x]], {x, 0, n}]; Table[a[n], {n, 27}]

Formula

G.f.: g(g(x)), where g(x) = Sum_{k>=1} mu(k)^2*x^k/(1 - x^k)^2 is the g.f. of A001615.
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