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.

A263177 Decimal expansion of a constant related to A263137.

Original entry on oeis.org

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

Views

Author

Vaclav Kotesovec, Oct 11 2015

Keywords

Examples

			0.0960101036186695795680588847641594939129540181270663556962564550198...
		

Crossrefs

Programs

  • Mathematica
    NIntegrate[E^(-x)/(1-E^(-4*x))^2/x - 1/(16*x^3) - 3/(16*x^2) - 19*E^(-x)/(96*x), {x, 0, Infinity}, WorkingPrecision -> 120, MaxRecursion -> 100, PrecisionGoal -> 110]

Formula

Integral_{x=0..infinity} exp(-x)/(x*(1 - exp(-4*x))^2) - 1/(16*x^3) - 3/(16*x^2) - 19/(96*x*exp(x)) dx.
A263176 + A263177 = log(Gamma(1/4))/2 - Zeta'(-1)/4 - 2*log(2)/3 - log(Pi)/4 = -0.062914043561495455491893116973161914641792581828767341125... . - Vaclav Kotesovec, Oct 12 2015

A263136 Expansion of Product_{k>=1} 1/(1-x^(4*k-1))^k.

Original entry on oeis.org

1, 0, 0, 1, 0, 0, 1, 2, 0, 1, 2, 3, 1, 2, 6, 5, 2, 6, 11, 7, 6, 15, 21, 12, 15, 30, 34, 22, 35, 58, 59, 43, 70, 108, 95, 85, 142, 187, 161, 167, 263, 318, 274, 318, 480, 534, 471, 595, 836, 879, 819, 1081, 1433, 1442, 1429, 1915, 2391, 2365, 2483, 3314, 3947
Offset: 0

Views

Author

Vaclav Kotesovec, Oct 10 2015

Keywords

Crossrefs

Programs

  • Maple
    with(numtheory):
    a:= proc(n) option remember; `if`(n=0, 1, add(add(d*
          `if`(irem(d+4, 4, 'r')=3, r, 0), d=divisors(j))*a(n-j), j=1..n)/n)
        end:
    seq(a(n), n=0..100); # after Alois P. Heinz
  • Mathematica
    nmax = 100; CoefficientList[Series[Product[1/(1-x^(4k-1))^k, {k, 1, nmax}], {x, 0, nmax}], x]
    nmax = 100; CoefficientList[Series[E^Sum[1/j*x^(3*j)/(1 - x^(4*j))^2, {j, 1, nmax}], {x, 0, nmax}], x]

Formula

G.f.: exp(Sum_{j>=1} 1/j*x^(3*j)/(1 - x^(4*j))^2).
a(n) ~ Zeta(3)^(53/288) * exp(d41 - Pi^4/(6912*Zeta(3)) + Pi^2 * n^(1/3) / (48*Zeta(3)^(1/3)) + 3 * Zeta(3)^(1/3) * n^(2/3)/4) / (sqrt(3*Pi) * 2^(101/96) * n^(197/288)), where d41 = A263176 = Integral_{x=0..infinity} exp(-3*x)/(x*(1 - exp(-4*x))^2) - 1/(16*x^3) - 1/(16*x^2) + 5/(96*x*exp(x)) = -0.158924147180165035059952001737321408554746599955833696821824808027... .

A263139 Expansion of Product_{k>=1} (1+x^(4*k-3))^k.

Original entry on oeis.org

1, 1, 0, 0, 0, 2, 2, 0, 0, 3, 4, 1, 0, 4, 10, 6, 0, 5, 16, 14, 3, 6, 28, 32, 10, 7, 40, 63, 33, 11, 60, 112, 74, 23, 80, 187, 161, 56, 111, 300, 308, 131, 152, 455, 568, 295, 223, 672, 968, 607, 356, 967, 1609, 1186, 618, 1367, 2546, 2189, 1132, 1926, 3941
Offset: 0

Views

Author

Vaclav Kotesovec, Oct 10 2015

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 100; CoefficientList[Series[Product[(1+x^(4k-3))^k, {k, 1, nmax}], {x, 0, nmax}], x]
    nmax = 100; CoefficientList[Series[E^Sum[(-1)^(j+1)/j*x^j/(1 - x^(4*j))^2, {j, 1, nmax}], {x, 0, nmax}], x]

Formula

G.f.: exp(Sum_{j>=1} (-1)^(j+1)/j*x^j/(1 - x^(4*j))^2).
a(n) ~ 2^(83/96) * 3^(2/3) * Zeta(3)^(1/6) * exp(-Pi^4/(2304*Zeta(3)) + Pi^2 * 3^(2/3) * 2^(2/3) * n^(1/3) / (96*Zeta(3)^(1/3)) + Zeta(3)^(1/3) * 2^(-8/3) * 3^(4/3) * n^(2/3)) / (12 * sqrt(Pi) * n^(2/3)).
Showing 1-3 of 3 results.