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 1-4 of 4 results.

A376660 Decimal expansion of a constant related to the asymptotics of A376630 and A376631.

Original entry on oeis.org

2, 0, 4, 5, 3, 9, 0, 6, 9, 1, 8, 5, 2, 0, 5, 0, 6, 3, 9, 8, 9, 3, 7, 0, 4, 2, 4, 4, 3, 4, 2, 6, 0, 1, 2, 5, 2, 2, 6, 5, 9, 4, 8, 7, 9, 3, 4, 6, 7, 8, 3, 3, 1, 8, 7, 9, 9, 4, 6, 6, 2, 8, 7, 0, 9, 3, 4, 4, 5, 5, 6, 1, 7, 3, 3, 7, 1, 1, 0, 7, 1, 3, 9, 6, 9, 8, 9, 2, 2, 1, 6, 4, 8, 1, 4, 2, 5, 3, 9, 5, 2, 5, 2, 8, 0, 9
Offset: 1

Views

Author

Vaclav Kotesovec, Oct 01 2024

Keywords

Examples

			2.045390691852050639893704244342601252265948793467833187994662870934455617...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[E^Sqrt[3*Log[r]^2/4 + 2*PolyLog[2, r^(1/2)] - Pi^2/6] /. r -> (-2 + ((29 - 3*Sqrt[93])/2)^(1/3) + ((29 + 3*Sqrt[93])/2)^(1/3))/3, 10, 120][[1]] (* Vaclav Kotesovec, Oct 07 2024 *)

Formula

Equals limit_{n->infinity} A376630(n)^(1/sqrt(n)).
Equals limit_{n->infinity} A376631(n)^(1/sqrt(n)).
Equals A376815^(1/2). - Vaclav Kotesovec, Oct 06 2024
Equals exp(sqrt(3*log(r)^2/4 + 2*polylog(2, r^(1/2)) - Pi^2/6)), where r = A088559 = 0.4655712318767680266567312252199... is the real root of the equation r*(1+r)^2 = 1. - Vaclav Kotesovec, Oct 07 2024

A376580 G.f.: Sum_{k>=0} x^(k^2) * Product_{j=1..k} (1 + x^(2*j-1))^2.

Original entry on oeis.org

1, 1, 2, 1, 1, 2, 1, 2, 4, 3, 3, 3, 3, 4, 4, 5, 5, 7, 9, 7, 8, 9, 9, 10, 11, 12, 13, 14, 15, 18, 17, 19, 24, 23, 25, 27, 28, 31, 32, 33, 37, 40, 42, 44, 47, 52, 54, 59, 62, 67, 75, 75, 80, 87, 90, 95, 102, 109, 114, 119, 127, 134, 142, 150, 159, 171, 178, 187, 199, 211
Offset: 0

Views

Author

Vaclav Kotesovec, Sep 29 2024

Keywords

Crossrefs

Programs

  • Mathematica
    nmax=100; CoefficientList[Series[Sum[x^(k^2)*Product[1+x^(2*j-1), {j, 1, k}]^2, {k, 0, Sqrt[nmax]}], {x, 0, nmax}], x]

Formula

a(n) ~ c * A376621^sqrt(n) / sqrt(n), where c = 1/(2*sqrt(3 - 4*sinh(arcsinh(3^(3/2)/2) / 3) / sqrt(3))) = 0.390989767113799449629...
a(n) ~ c * A376542(n), where c = (108 + 12*sqrt(93))^(1/3)/3 - 4/(108 + 12*sqrt(93))^(1/3) = 1.364655607... is the real root of the equation c*(4 + c^2) = 8.
a(n) ~ c * A369557(n), where c = A347178 = -sinh(log((-3*sqrt(3) + sqrt(31))/2)/3) / sqrt(3) = 0.3411639019... is the real root of the equation 2*c*(1 + 4*c^2) = 1.
a(n) ~ A376631(n) * (A376621/A376660)^sqrt(n).

A376627 G.f.: Sum_{k>=0} x^(k*(k+1)/2) * Product_{j=1..k} (1 + x^(2*j))^2.

Original entry on oeis.org

1, 1, 0, 3, 0, 3, 1, 3, 2, 4, 4, 3, 8, 2, 10, 2, 14, 2, 19, 3, 20, 7, 23, 11, 26, 17, 25, 26, 27, 35, 29, 48, 27, 64, 28, 81, 30, 98, 32, 119, 37, 139, 47, 159, 59, 183, 77, 199, 105, 217, 137, 237, 180, 251, 232, 266, 292, 281, 364, 293, 447, 309, 540, 331, 645, 350
Offset: 0

Views

Author

Vaclav Kotesovec, Sep 30 2024

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 100; CoefficientList[Series[Sum[x^(k*(k+1)/2)*Product[1+x^(2*j), {j, 1, k}]^2, {k, 0, Sqrt[2*nmax]}], {x, 0, nmax}], x]
    nmax = 100; p = 1; s = 1; Do[p = Expand[p*(1 + x^(2*k))*(1 + x^(2*k))*x^k]; p = Take[p, Min[nmax + 1, Exponent[p, x] + 1, Length[p]]]; s += p;, {k, 1, Sqrt[2*nmax]}]; Take[CoefficientList[s, x], nmax + 1]

Formula

G.f.: Sum_{k>=0} Product_{j=1..k} (1 + x^(2*j))^2 * x^j.
a(n) ~ c * A376659^sqrt(n) / sqrt(n), where c = sqrt(5/168 + sqrt(11/23) * cosh(arccosh(17*sqrt(23)/(2*11^(3/2)))/3)/21) = 0.2512284115765342169430117...

A376632 G.f.: Sum_{k>=0} x^(k^2) * Product_{j=1..k} (1 + x^(2*j)).

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 1, 0, 2, 1, 1, 1, 1, 1, 1, 2, 0, 2, 1, 2, 1, 2, 1, 2, 2, 1, 2, 1, 3, 2, 3, 1, 3, 1, 3, 2, 3, 2, 3, 3, 2, 4, 3, 4, 2, 4, 2, 5, 3, 5, 2, 5, 3, 5, 4, 4, 5, 5, 5, 5, 6, 4, 7, 4, 7, 4, 8, 4, 8, 5, 8, 6, 8, 6, 9, 7, 8, 8, 8, 9, 8, 10
Offset: 0

Views

Author

Vaclav Kotesovec, Sep 30 2024

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 100; CoefficientList[Series[Sum[x^(k^2)*Product[1+x^(2*j), {j, 1, k}], {k, 0, Sqrt[nmax]}], {x, 0, nmax}], x]
    nmax = 100; p = 1; s = 1; Do[p = Expand[p*(1 + x^(2*k))*x^(2*k - 1)]; p = Take[p, Min[nmax + 1, Exponent[p, x] + 1, Length[p]]]; s += p;, {k, 1, Sqrt[nmax]}]; Take[CoefficientList[s, x], nmax + 1]

Formula

a(n) ~ sqrt(1 + 3/sqrt(5)) * exp(Pi*sqrt(n/30)) / (4*sqrt(n)).
Showing 1-4 of 4 results.