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.

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A019842 Decimal expansion of sine of 33 degrees.

Original entry on oeis.org

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

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Author

Keywords

Comments

This sequence is also decimal expansion of cosine of 57 degrees. - Mohammad K. Azarian, Jun 29 2013
An algebraic number of degree 16 and denominator 2. - Charles R Greathouse IV, Aug 27 2017

Programs

Formula

Equals A019831 * A019888 + A019820 * A019877 = (1/2) * A019896 + A019812 * A010527. - R. J. Mathar, Jan 27 2021

A019844 Decimal expansion of sine of 35 degrees.

Original entry on oeis.org

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

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Author

Keywords

Comments

This sequence is also decimal expansion of cosine of 55 degrees. - Mohammad K. Azarian, Jun 29 2013

Programs

  • Mathematica
    RealDigits[Sin[35 Degree],10,120][[1]] (* Harvey P. Dale, Mar 26 2013 *)
  • PARI
    sin(35*Pi/180) \\ Michel Marcus, Aug 11 2014

Formula

Equals A019837 * A019892 + A019816 * A019871 = (1/2)* A019894 + A019814 * A010527. - R. J. Mathar, Jan 27 2021

A041132 Numerators of continued fraction convergents to sqrt(75).

Original entry on oeis.org

8, 9, 17, 26, 433, 459, 892, 1351, 22508, 23859, 46367, 70226, 1169983, 1240209, 2410192, 3650401, 60816608, 64467009, 125283617, 189750626, 3161293633, 3351044259, 6512337892, 9863382151, 164326452308, 174189834459, 338516286767, 512706121226, 8541814226383
Offset: 0

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Author

Keywords

Crossrefs

Programs

  • Mathematica
    Numerator[Convergents[Sqrt[75], 30]] (* Vincenzo Librandi, Oct 29 2013 *)

Formula

G.f.: -(x^7-8*x^6+9*x^5-17*x^4-26*x^3-17*x^2-9*x-8) / (x^8-52*x^4+1). - Colin Barker, Nov 05 2013

Extensions

More terms from Colin Barker, Nov 05 2013

A093604 Decimal expansion of D/2, where D^2 = 3*sqrt(3)/Pi.

Original entry on oeis.org

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

Views

Author

Lekraj Beedassy, May 14 2004

Keywords

Comments

D/2=sqrt(3*sqrt(3)/Pi)/2 corresponds to the radius of the area-bisecting concentric circle within the unit-sided hexagon.

Examples

			sqrt(3*sqrt(3)/Pi)/2 = 0.6430370685787437846417825056651579788623049833326304871239...
		

Crossrefs

Cf. A097603, A010527, A011002, A087197. - R. J. Mathar, Feb 06 2009

Programs

Extensions

Removed leading zero and adjusted offset - R. J. Mathar, Feb 06 2009
Corrected and extended by Harvey P. Dale, Aug 27 2017

A220351 Decimal expansion of (3*sqrt(3)+sqrt(7))/10.

Original entry on oeis.org

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

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Author

Keywords

Comments

Smith & Smith conjecture that this is the Steiner ratio rho_3, the least upper bound on the ratio of the length of the Steiner minimal tree to the length of the minimal tree in dimension 3. Diaconis & Graham offer $1000 for proof (or disproof) of this conjecture.
This is an algebraic number of degree 4; the minimal polynomial is 25x^4 - 17x^2 + 1.

Examples

			0.7841903733771222471083954778156877526538674944513592064535755...
		

References

  • Persi Diaconis and R. L. Graham, Magical Mathematics: The Mathematical Ideas that Animate Great Magic Tricks, Princeton University Press, 2011. See pp. 212-214.
  • Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 8.6 Steiner Tree Constants, p. 504.

Crossrefs

Cf. A010527.

Programs

Formula

(3*sqrt(3)+sqrt(7))/10.

Extensions

Formula and name simplified by Jean-François Alcover, May 27 2014

A277754 Decimal expansion of Sum_{n>=1} sin((n*Pi)/3)^n.

Original entry on oeis.org

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

Views

Author

Michelle Huff, Oct 28 2016

Keywords

Comments

The sum of four easily recognized geometric series that have common ratio 9/64.
An algebraic number with minimal polynomial 1369x^2 - 6216x + 6468. - Charles R Greathouse IV, Oct 29 2016

Examples

			2.92564084610714275971308780...
		

Crossrefs

Programs

  • Mathematica
    r = Sqrt[3]/2; u = Simplify[r (1 + r + r^3 - r^4)/(1 - r^6)]
    RealDigits[N[u, 120], 10][[1]]
  • PARI
    suminf(n=1, sin((n*Pi)/3)^n) \\ Michel Marcus, Oct 29 2016
    
  • PARI
    (sqrt(3)+6)*14/37 \\ Charles R Greathouse IV, Oct 29 2016

Formula

Equals (14/37)*(6 + sqrt(3)).

A277755 Decimal expansion of Sum_{n>=1} |sin((n*Pi)/3)|^n.

Original entry on oeis.org

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

Views

Author

Michelle Huff, Oct 28 2016

Keywords

Examples

			(2/37)*(42 + 25 Sqrt[3]) = 4.61087946968767201828033289392685454992..., the sum of two easily recognized geometric series that have common ratio (3/4)^(3/2).
		

Crossrefs

Programs

  • Mathematica
    r = Sqrt[3]/2; u = Simplify[r (1 + r)/(1 - r^3)]
    RealDigits[N[u, 1200], 10][[1]]
  • PARI
    suminf(n=1, abs(sin((n*Pi)/3))^n) \\ Michel Marcus, Oct 29 2016

A325732 First term of n-th difference sequence of (floor(k*r)), r = sqrt(3/4), k >= 0.

Original entry on oeis.org

0, 1, -1, 1, -1, 1, -1, 0, 7, -35, 119, -329, 791, -1715, 3430, -6419, 11319, -18767, 28763, -38759, 38759, 1, -149228, 572057, -1615429, 3979001, -9014851, 19251001, -39309301, 77558760, -149239771, 282712561, -532577025, 1008032953, -1934671809, 3787949521
Offset: 1

Views

Author

Clark Kimberling, May 20 2019

Keywords

Crossrefs

Cf. A325664. Inverse binomial Transform of A171970 and A172475.
Cf. A010527 (sqrt(3/4)).

Programs

  • Mathematica
    Table[First[Differences[Table[Floor[Sqrt[3/4]*n], {n, 0, 50}], n]], {n, 1, 50}]

A343055 Decimal expansion of the imaginary part of i^(1/16), or sin(Pi/32).

Original entry on oeis.org

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

Views

Author

Seiichi Manyama, Apr 04 2021

Keywords

Comments

An algebraic number of degree 16 and denominator 2. - Charles R Greathouse IV, Jan 09 2022

Examples

			0.09801714032956060199419...
		

Crossrefs

sin(Pi/m): A010527 (m=3), A010503 (m=4), A019845 (m=5), A323601 (m=7), A182168 (m=8), A019829 (m=9), A019827 (m=10), A019824 (m=12), A232736 (m=14), A019821 (m=15), A232738 (m=16), A241243 (m=17), A019819 (m=18), A019818 (m=20), A343054 (m=24), A019815 (m=30), this sequence (m=32), A019814 (m=36).

Programs

  • Mathematica
    RealDigits[Sin[Pi/32], 10, 100, -1][[1]] (* Amiram Eldar, Apr 27 2021 *)
  • PARI
    imag(I^(1/16))
    
  • PARI
    sin(Pi/32)
    
  • PARI
    sqrt(2-sqrt(2+sqrt(2+sqrt(2))))/2
    
  • Sage
    numerical_approx(sin(pi/32), digits=123) # G. C. Greubel, Sep 30 2022

Formula

Equals (1/2) * sqrt(2-sqrt(2+sqrt(2+sqrt(2)))).
One of the 16 real roots of -128*x^2 +2688*x^4 -21504*x^6 +84480*x^8 +32768*x^16 -131072*x^14 +212992*x^12 -180224*x^10 +1 =0. - R. J. Mathar, Aug 29 2025
Equals A232738/(2*A343056). - R. J. Mathar, Sep 05 2025

A343056 Decimal expansion of the real part of i^(1/16), or cos(Pi/32).

Original entry on oeis.org

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

Views

Author

Seiichi Manyama, Apr 04 2021

Keywords

Examples

			0.9951847266721968862448369...
		

Crossrefs

cos(Pi/m): A010503 (m=4), A019863 (m=5), A010527 (m=6), A073052 (m=7), A144981 (m=8), A019879 (m=9), A019881 (m=10), A019884 (m=12), A232735 (m=14), A019887 (m=15), A232737 (m=16), A210649 (m=17), A019889 (m=18), A019890 (m=20), A144982 (m=24), A019893 (m=30). this sequence (m=32), A019894 (m=36).

Programs

  • Magma
    R:= RealField(127); Cos(Pi(R)/32); // G. C. Greubel, Sep 30 2022
    
  • Mathematica
    RealDigits[Cos[Pi/32], 10, 100][[1]] (* Amiram Eldar, Apr 27 2021 *)
  • PARI
    real(I^(1/16))
    
  • PARI
    cos(Pi/32)
    
  • PARI
    sqrt(2+sqrt(2+sqrt(2+sqrt(2))))/2
    
  • SageMath
    numerical_approx(cos(pi/32), digits=122) # G. C. Greubel, Sep 30 2022

Formula

Equals (1/2) * sqrt(2+sqrt(2+sqrt(2+sqrt(2)))).
Satisfies 32768*x^16 -131072*x^14 +212992*x^12 -180224*x^10 +84480*x^8 -21504*x^6 +2688*x^4 -128*x^2 +1 = 0. - R. J. Mathar, Aug 29 2025
Equals 2F1(-1/16,1/16;1/2;1/2). - R. J. Mathar, Aug 31 2025
Previous Showing 71-80 of 89 results. Next