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.

Showing 1-3 of 3 results.

A336439 a(n) = (n!)^n * [x^n] -log(Sum_{k>=0} (-x)^k / (k!)^n).

Original entry on oeis.org

0, 1, 1, 46, 63111, 4226436876, 21095962423437280, 11165885881625823212655540, 846105231095934499366980692096995455, 11911559696594230804398683820096471009503594129080, 39208751872375132639833577214095359308827747721266594509276656136
Offset: 0

Views

Author

Ilya Gutkovskiy, Jul 21 2020

Keywords

Crossrefs

Programs

  • Mathematica
    Table[(n!)^n SeriesCoefficient[-Log[Sum[(-x)^k/(k!)^n, {k, 0, n}]], {x, 0, n}], {n, 0, 10}]
    b[n_, k_] := If[n == 0, 0, (-1)^(n + 1) - (1/n) Sum[(-1)^(n - j) Binomial[n, j]^k j b[j, k], {j, 1, n - 1}]];a[n_] := b[n, n]; Table[a[n], {n, 0, 10}]

A336427 a(0) = 0; a(n) = 1 + (1/n) * Sum_{k=1..n-1} binomial(n,k)^3 * k * a(k).

Original entry on oeis.org

0, 1, 5, 100, 5357, 597726, 120049592, 39381634818, 19686000625517, 14233714132535146, 14293760060523962630, 19298235276251711246358, 34108177389621376109912120, 77181320123960021972892515094, 219430688163572488543090308547898
Offset: 0

Views

Author

Ilya Gutkovskiy, Jul 21 2020

Keywords

Crossrefs

Programs

  • Mathematica
    a[0] = 0; a[n_] := a[n] = 1 + (1/n) Sum[Binomial[n, k]^3 k a[k], {k, 1, n - 1}]; Table[a[n], {n, 0, 14}]
    nmax = 14; CoefficientList[Series[-Log[1 - Sum[x^k/(k!)^3, {k, 1, nmax}]], {x, 0, nmax}], x] Range[0, nmax]!^3

Formula

Sum_{n>=0} a(n) * x^n / (n!)^3 = -log(1 - Sum_{n>=1} x^n / (n!)^3).

A336436 a(0) = 0; a(n) = ((n-1)!)^3 + (1/n) * Sum_{k=1..n-1} (binomial(n,k) * (n-k-1)!)^3 * k * a(k).

Original entry on oeis.org

0, 1, 5, 107, 6020, 701424, 146665984, 50005133576, 25952660212352, 19469692241358336, 20277424971134267904, 28384315863525074792448, 52002222667299924427689984, 121958564445078246232792363008, 359324017883943122680656621023232
Offset: 0

Views

Author

Ilya Gutkovskiy, Jul 21 2020

Keywords

Crossrefs

Programs

  • Mathematica
    a[0] = 0; a[n_] := a[n] = ((n - 1)!)^3 + (1/n) Sum[(Binomial[n, k] (n - k - 1)!)^3 k a[k], {k, 1, n - 1}]; Table[a[n], {n, 0, 14}]
    nmax = 14; CoefficientList[Series[-Log[1 - Sum[x^k/k^3, {k, 1, nmax}]], {x, 0, nmax}], x] Range[0, nmax]!^3

Formula

Sum_{n>=0} a(n) * x^n / (n!)^3 = -log(1 - Sum_{n>=1} x^n / n^3).
Showing 1-3 of 3 results.