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 1-6 of 6 results.

A353818 Product_{n>=1} (1 + a(n)*x^n/n!) = 1 + arcsin(x).

Original entry on oeis.org

1, 0, 1, -4, 29, -174, 1583, -13168, 144153, -1485330, 20127867, -253341144, 3978820221, -57986205900, 1057400360235, -18016221644544, 370244721585681, -6993826454599146, 162968423791332339, -3490951922268853320, 88052648301403014789, -2075060448716599488276
Offset: 1

Views

Author

Ilya Gutkovskiy, May 08 2022

Keywords

Crossrefs

Programs

  • Mathematica
    nn = 22; f[x_] := Product[(1 + a[n] x^n/n!), {n, 1, nn}]; sol = SolveAlways[0 == Series[f[x] - 1 - ArcSin[x], {x, 0, nn}], x]; Table[a[n], {n, 1, nn}] /. sol // Flatten

A353820 Product_{n>=1} (1 + a(n)*x^n/n!) = 1 + arctan(x).

Original entry on oeis.org

1, 0, -2, 8, -16, 96, -832, 9344, -27648, 238080, -4228608, 55812096, -398991360, 4930609152, -98606039040, 2440552022016, -17762113880064, 235149341884416, -7331825098948608, 170578782435409920, -2009778629489197056, 38563016760590598144, -1278044473427380666368
Offset: 1

Views

Author

Ilya Gutkovskiy, May 08 2022

Keywords

Crossrefs

Programs

  • Mathematica
    nn = 23; f[x_] := Product[(1 + a[n] x^n/n!), {n, 1, nn}]; sol = SolveAlways[0 == Series[f[x] - 1 - ArcTan[x], {x, 0, nn}], x]; Table[a[n], {n, 1, nn}] /. sol // Flatten

A353821 Product_{n>=1} (1 + a(n)*x^n/n!) = 1 + arctanh(x).

Original entry on oeis.org

1, 0, 2, -8, 64, -384, 3968, -34432, 414720, -4454400, 68247552, -912236544, 15949529088, -245572583424, 5012834549760, -92436465352704, 2119956936523776, -42836227522560000, 1123874181449515008, -26161653829651660800, 730049769522063212544, -18719979459270521389056
Offset: 1

Views

Author

Ilya Gutkovskiy, May 08 2022

Keywords

Crossrefs

Programs

  • Mathematica
    nn = 22; f[x_] := Product[(1 + a[n] x^n/n!), {n, 1, nn}]; sol = SolveAlways[0 == Series[f[x] - 1 - ArcTanh[x], {x, 0, nn}], x]; Table[a[n], {n, 1, nn}] /. sol // Flatten

A353914 Product_{n>=1} 1 / (1 - a(n)*x^n/n!) = 1 + arcsinh(x).

Original entry on oeis.org

1, -2, -1, -20, -11, 46, -547, -29840, -27351, 232818, -3258663, -29911848, -390445563, 4450393260, -84140635815, -12153983817984, -18431412645519, 286688710444842, -6436900596281679, -169286474970429624, -2208721087854287811, 41892263643715799796, -1149793471388581053219
Offset: 1

Views

Author

Ilya Gutkovskiy, May 10 2022

Keywords

Crossrefs

Programs

  • Mathematica
    nn = 23; f[x_] := Product[1/(1 - a[n] x^n/n!), {n, 1, nn}]; sol = SolveAlways[0 == Series[f[x] - 1 - ArcSinh[x], {x, 0, nn}], x]; Table[a[n], {n, 1, nn}] /. sol // Flatten

A354116 Product_{n>=1} 1 / (1 - x^n)^(a(n)/n!) = 1 + arcsinh(x).

Original entry on oeis.org

1, -2, -1, 4, -11, 116, -547, 960, -7751, 414384, -3258663, -6813696, -390445563, 9694641984, -964154427, 208258646016, -18431412645519, 207842731632384, -6436900596281679, -37454668211552256, 834261829219880829, 91517388643567641600, -1149793471388581053219
Offset: 1

Views

Author

Ilya Gutkovskiy, May 17 2022

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 23; CoefficientList[Series[Sum[MoebiusMu[k] Log[1 + ArcSinh[x^k]]/k, {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]! // Rest

Formula

E.g.f.: Sum_{k>=1} mu(k) * log(1 + arcsinh(x^k)) / k.

A354274 Product_{n>=1} (1 + x^n)^(a(n)/n!) = 1 + arcsinh(x).

Original entry on oeis.org

1, 0, -1, 4, -11, -4, -547, 7680, -7751, 81744, -3258663, -9474816, -390445563, 233029824, -964154427, 4193551958016, -18431412645519, 71090090006784, -6436900596281679, 17349989459410944, 834261829219880829, -241960391975347200, -1149793471388581053219
Offset: 1

Views

Author

Ilya Gutkovskiy, May 22 2022

Keywords

Crossrefs

Programs

  • Mathematica
    b[n_, i_] := b[n, i] = If[n == 0, 1, If[i < 1, 0, Sum[Binomial[c[i], j] b[n - i j, i - 1], {j, 0, n/i}]]]; c[n_] := c[n] = {1, 0, -1, 0}[[Mod[n, 4, 1]]] (n - 2)!!/(n (n - 1)!!) - b[n, n - 1]; a[n_] := n! c[n]; Table[a[n], {n, 1, 23}]

Formula

E.g.f.: Sum_{k>=1} A067856(k) * log(1 + arcsinh(x^k)) / k.
Showing 1-6 of 6 results.