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 1-10 of 12 results. Next

A049470 Decimal expansion of cos(1).

Original entry on oeis.org

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

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Author

Albert du Toit (dutwa(AT)intekom.co.za), N. J. A. Sloane

Keywords

Comments

Also, decimal expansion of the real part of e^i. - Bruno Berselli, Feb 08 2013
By the Lindemann-Weierstrass theorem, this constant is transcendental. - Charles R Greathouse IV, May 13 2019

Examples

			0.5403023058681397...
		

Crossrefs

Cf. A049469 (imaginary part of e^i), A211883 (real part of -(i^e)), A211884 (imaginary part of -(i^e)). - Bruno Berselli, Feb 08 2013
Cf. A073743 ( cosh(1) ), A073448, A275651.

Programs

Formula

Continued fraction representation: cos(1) = 1/(1 + 1/(1 + 2/(11 + 12/(29 + ... + (2*n - 2)*(2*n - 3)/((4*n^2 - 2*n - 1) + ... ))))). See A275651 for proof. Cf. A073743. - Peter Bala, Sep 02 2016
Equals Sum_{k >= 0} (-1)^k/A010050(k), where A010050(k) = (2k)! [See Gradshteyn and Ryzhik]. - A.H.M. Smeets, Sep 22 2018
Equals 1/A073448. - Alois P. Heinz, Jan 23 2023
From Gerry Martens, May 04 2024: (Start)
Equals (4*(cos(1/4)^4 + sin(1/4)^4) - 3).
Equals (16*(cos(1/4)^6 + sin(1/4)^6) - 10)/6. (End)

A073449 Decimal expansion of cot(1).

Original entry on oeis.org

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

Views

Author

Rick L. Shepherd, Aug 01 2002

Keywords

Comments

By the Lindemann-Weierstrass theorem, this constant is transcendental. - Charles R Greathouse IV, May 13 2019

Examples

			0.64209261593433070300641998659...
		

Crossrefs

Cf. A049471 (tan(1)=1/A073449), A049469 (sin(1)), A049470 (cos(1)), A073447 (csc(1)), A073448 (sec(1)).

Programs

  • Mathematica
    RealDigits[Cot[1], 10, 100][[1]] (* Amiram Eldar, May 15 2021 *)
  • PARI
    cotan(1)

Formula

Equals Sum_{k>=0} (-1)^k * B(2*k) * 2^(2*k) / (2*k)!, where B(k) is the k-th Bernoulli number. - Amiram Eldar, May 15 2021

A073447 Decimal expansion of csc(1).

Original entry on oeis.org

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

Views

Author

Rick L. Shepherd, Aug 01 2002

Keywords

Comments

By the Lindemann-Weierstrass theorem, this constant is transcendental. - Charles R Greathouse IV, May 13 2019

Examples

			1.18839510577812121626159945237...
		

Crossrefs

Cf. A049469 (sin(1)=1/A073447), A049470 (cos(1)), A049471 (tan(1)), A073448 (sec(1)), A073449 (cot(1)).

Programs

  • Mathematica
    RealDigits[Csc[1], 10, 120][[1]] (* Amiram Eldar, May 29 2023 *)
  • PARI
    1/sin(1)

Formula

Equals Sum_{n=-oo..oo} ((-1)^n/(1 + n*Pi)). - Jean-François Alcover, Mar 21 2013.
Equals Sum_{k>=0} (-1)^k * (2 - 4^k) * bernoulli(2*k)/(2*k)! = Sum_{k>=0} (-1)^k * (2 - 4^k) * A027641(2*k)/(A027642(2*k)*(2*k)!). - Amiram Eldar, Aug 03 2020

A222480 Decimal expansion of cos(1)/(1+cos(1)).

Original entry on oeis.org

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

Views

Author

Alois P. Heinz, Feb 21 2013

Keywords

Comments

By the Lindemann-Weierstrass theorem, this constant is transcendental. - Charles R Greathouse IV, May 13 2019

Examples

			0.35077679479523758155811675...
		

Crossrefs

Cf. A222481 (continued fraction), A222482 (Engel expansion), A049470 (cos(1)), A073448 (1/cos(1)).

Programs

  • Maple
    s:= convert(evalf(1/(1+1/cos(1)), 140), string):
    seq(parse(s[n+2]), n=0..122);
  • PARI
    1/(1+1/cos(1)) \\ Charles R Greathouse IV, May 13 2019

Formula

cos(1)/(1+cos(1)) = 1/(1+1/cos(1)) = 1/(1+sec(1)).

A222481 Continued fraction for cos(1)/(1+cos(1)).

Original entry on oeis.org

0, 2, 1, 5, 1, 2, 2, 1, 2, 1, 1, 40, 4, 3, 1, 3, 4, 46, 3, 5, 2, 12, 3, 1, 4, 11, 1, 3, 3, 106, 2, 1, 1, 2, 28, 1, 7, 32, 3, 42, 1, 9, 1, 4, 2, 2, 1, 1, 15, 1, 5, 1, 8, 1, 1, 1, 3, 1, 7, 18, 13, 1, 1, 1, 1, 1, 5, 9, 7, 3, 3, 1, 1, 18, 6, 5, 1, 11, 1, 1, 10, 2
Offset: 0

Views

Author

Alois P. Heinz, Feb 21 2013

Keywords

Comments

Essentially the same as A068115: a(n) = A068115(n) for n != 2.

Examples

			0.35077679479523758155811675...
		

Crossrefs

Cf. A222480 (decimal expansion), A222482 (Engel expansion), A049470 (cos(1)), A073448 (1/cos(1)), A068115.

Programs

  • Maple
    numtheory[cfrac](evalf(1/(1+1/cos(1)), 250), 130, 'quotients')[];

Formula

cos(1)/(1+cos(1)) = 1/(1+1/cos(1)) = 1/(1+sec(1)).

Extensions

Offset changed by Andrew Howroyd, Jul 03 2024

A222482 Engel expansion of cos(1)/(1+cos(1)).

Original entry on oeis.org

3, 20, 22, 40, 68, 248, 7163, 28663, 50059, 64574, 638169, 761733, 2537764, 2925739, 3363073, 4977902, 5646039, 57212854, 159650555, 219684539, 453524713, 459239955, 2002180165, 3234082460, 14965375439, 50298730245, 89316768769, 464076054936, 520232391320
Offset: 1

Views

Author

Alois P. Heinz, Feb 21 2013

Keywords

Comments

Cf. A006784 for definition of Engel expansion.

Examples

			0.35077679479523758155811675...
		

Crossrefs

Cf. A222480 (decimal expansion), A222481 (continued fraction), A049470 (cos(1)), A073448 (1/cos(1)).

Programs

  • Maple
    Digits:= 1000:
    b:= evalf(1/(1+1/cos(1))):  engel:= (r, n)-> `if`(n=0 or r=0, NULL, [ceil(1/r), engel(r*ceil(1/r)-1, n-1)][]):
    engel(b, 39);

Formula

cos(1)/(1+cos(1)) = 1/(1+1/cos(1)) = 1/(1+sec(1)).

A346839 Decimal expansion of Sum_{n>=0} A346838(n) / n!.

Original entry on oeis.org

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

Views

Author

Peter Luschny, Aug 13 2021

Keywords

Examples

			0.29340799302602338740477843394029002038314588271248926...
		

Crossrefs

Programs

  • Maple
    A := n -> I*(polylog(-n, -I) - exp(I*Pi*n)*polylog(-n, I)) / exp(I*Pi*n/2):
    Digits := 120; sum(A(n)/n!, n = 0..infinity): evalf(%)*10^91:
    ListTools:-Reverse(convert(floor(%), base, 10));
  • Mathematica
    RealDigits[Sec[1] - Tan[1], 10 , 100][[1]] (* Amiram Eldar, Aug 17 2021 *)

Formula

Equals sec(1) - tan(1) = A073448 - A049471. - Amiram Eldar, Aug 17 2021

A117041 Decimal expansion of (cos 1)^(-2)=(sec(1))^2.

Original entry on oeis.org

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

Views

Author

Mohammad K. Azarian, Apr 16 2006

Keywords

Comments

By the Lindemann-Weierstrass theorem, this constant is transcendental. - Charles R Greathouse IV, May 13 2019

Examples

			3.42551882081475976094167893354113664805374743205738476586851476
		

Crossrefs

Programs

A117042 Decimal expansion of (cos 1)^(-3)=(sec(1))^3.

Original entry on oeis.org

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

Views

Author

Mohammad K. Azarian, Apr 16 2006

Keywords

Comments

By the Lindemann-Weierstrass theorem, this constant is transcendental. - Charles R Greathouse IV, May 13 2019

Examples

			6.340004074775787630861652711841658616429223645815934292875740623000
		

Crossrefs

Programs

A117043 Decimal expansion of (cos 1)^(-4)=(sec(1))^4.

Original entry on oeis.org

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

Views

Author

Mohammad K. Azarian, Apr 16 2006

Keywords

Comments

By the Lindemann-Weierstrass theorem, this constant is transcendental. - Charles R Greathouse IV, May 13 2019

Examples

			11.7341791917561421904326776865351274688644805049446095726008918896
		

Crossrefs

Programs

Showing 1-10 of 12 results. Next