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 1-7 of 7 results.

A099287 Decimal expansion of the complementary error function at 1.

Original entry on oeis.org

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

Views

Author

Robert G. Wilson v, Oct 11 2004

Keywords

Examples

			0.157299207050285130658779364917390740703933002033697091540062102165...
		

Programs

  • Mathematica
    RealDigits[ Erfc[1], 10, 105][[1]]

Formula

A333419 Decimal expansion of the error function at 1/2, erf(1/2).

Original entry on oeis.org

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

Views

Author

Sean A. Irvine, Mar 20 2020

Keywords

Examples

			0.5204998778130465376827466538919645287364515757579637...
		

Crossrefs

Cf. A099286 (erf(1)).

Programs

A222392 Decimal expansion of Sum_{n>=1} 1/Gamma(n/2).

Original entry on oeis.org

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

Views

Author

Bruno Berselli, Mar 19 2013

Keywords

Examples

			5.57316966431003975325790404977558240053838531356466534303248120641829030...
		

References

  • Jerome Spanier and Keith B. Oldham, "Atlas of Functions", Hemisphere Publishing Corp., 1987, chapter 43, equation 43:5:12 at page 415.

Crossrefs

Cf. A222391.
Cf. A001113, (Sum_{n>=1} 1/Gamma(n)).

Programs

  • Mathematica
    RealDigits[(1 + Erf[1]) E + 1/Sqrt[Pi], 10, 90][[1]]

Formula

Equals (1+erf(1))*e+1/sqrt(Pi), where erf is the error function (see A099286).

A351400 Decimal expansion of e * erf(1), where erf is the error function.

Original entry on oeis.org

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

Views

Author

Amiram Eldar, Feb 10 2022

Keywords

Comments

The sum of reciprocals of the factorials of the positive half-integers.

Examples

			2.29069825230323823094953712686214731693708759053570...
		

References

  • Rudolf Gorenflo, Anatoly A. Kilbas, Francesco Mainardi, and Sergei Rogosin, Mittag-Leffler Functions, Related Topics and Applications, New York, NY: Springer, 2020. See p. 94, eq. (4.12.9.5).
  • Constantin Milici, Gheorghe Drăgănescu, and J. Tenreiro Machado, Fractional Differential Equations, Introduction to Fractional Differential Equations, Springer, Cham, 2019. See p. 12, eq. (1.9).

Crossrefs

Programs

  • Maple
    evalf(exp(1)*erf(1), 120);  # Alois P. Heinz, Feb 10 2022
  • Mathematica
    RealDigits[E * Erf[1], 10, 100][[1]]
  • PARI
    exp(1)*(1 - erfc(1)) \\ Michel Marcus, Feb 10 2022

Formula

Equals Sum_{k>=0} 1/(k + 1/2)! = Sum_{k>=1} 1/Gamma(k + 1/2).
Equals E_{1, 3/2}(1), where E_{a,b}(z) is the two-parameter Mittag-Leffler function.
Equals (1/sqrt(Pi)) * Sum_{k>=1} 2^k/(2*k-1)!! = (1/sqrt(Pi)) * Sum_{k>=1} A000079(k)/A001147(k).
Equals A001113 * A099286.
Equals A087197 * A125961.

A347151 Decimal expansion of erf(2).

Original entry on oeis.org

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

Views

Author

Sean A. Irvine, Aug 19 2021

Keywords

Examples

			0.995322265018952734162069256367252928610...
		

Crossrefs

Cf. A099286.

Programs

Formula

Equals (2/sqrt(Pi)) * Integral_{x=0..2} exp(-x^2) dx.
Equals (2/sqrt(Pi)) * Sum_{k>=0} (-1)^k * 2^(2*k+1) / (k! * (2*k+1)).

A349892 Decimal expansion of erf(1/e).

Original entry on oeis.org

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

Views

Author

Christoph B. Kassir, Dec 04 2021

Keywords

Examples

			0.3971176949815771696929038299166076792335...
		

Crossrefs

Programs

  • Maple
    evalf(erf(exp(-1)), 120);  # Alois P. Heinz, Dec 13 2021
  • Mathematica
    RealDigits[Erf[1/E], 10, 100][[1]] (* Amiram Eldar, Dec 04 2021 *)
  • PARI
    1 - erfc(1/exp(1)) \\ Michel Marcus, Dec 04 2021

A378942 Decimal expansion of (1/sqrt(Pi) + e*erfc(-1))/2.

Original entry on oeis.org

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

Views

Author

Stefano Spezia, Dec 11 2024

Keywords

Examples

			2.7865848321550198766289520248877912002691926567823...
		

References

  • Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, 2003, Section 4.6, p. 262.

Crossrefs

Programs

  • Mathematica
    RealDigits[(1/Sqrt[Pi]+E Erfc[-1])/2,10,100][[1]]

Formula

Equals (1 + e*sqrt(Pi)*(1 + erf(1)))/(2*sqrt(Pi)).
Equals A222392 / 2. - Amiram Eldar, Feb 15 2025
Showing 1-7 of 7 results.