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 1-2 of 2 results.

A217572 Decimal expansion of the conversion factor from radians to arcseconds.

Original entry on oeis.org

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

Views

Author

R. J. Mathar, Oct 10 2012

Keywords

Comments

From Peter Munn, Aug 21 2020 and Nov 11 2020: (Start)
Corresponds to a significant mark labeled with a (typographic) double prime symbol on slide rule calculating devices in the 20th century. The Pickworth reference explains its use for sines and tangents of small angles.
As tangents of small angles can be approximated by the angle itself, this value approximates the cotangent of an arcsecond, and so, to within 1 part in 10^11, the number of astronomical units in a parsec, prior to its redefinition in August 2015. (End)
Equals the number of astronomical units in a parsec, as defined in 2015. - Donghwi Park, Aug 08 2021

Examples

			206264.806247096355156473...
		

References

  • C. N. Pickworth, The Slide Rule, 24th Ed., Pitman, London, 1945, pp. 76-78, Trigonometrical Applications.

Crossrefs

Related conversion factors: A155970 (arcseconds to radians), A072097 (radians to degrees), A337493 (radians to arcminutes).

Programs

  • Maple
    evalf(180/Pi*3600) ;
  • Mathematica
    RealDigits[(180/Pi) 3600, 10, 75][[1]] (* Bruno Berselli, Oct 10 2012 *)
  • Maxima
    fpprec:77; ev(bfloat((180/%pi)*3600)); /* Bruno Berselli, Oct 10 2012 */

Formula

Equals 3600 * A072097.
Equals 1/A155970.

A337493 Decimal expansion of 10800/Pi, number of minutes of arc in a radian.

Original entry on oeis.org

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

Views

Author

Peter Munn, Aug 29 2020

Keywords

Comments

Corresponds to a significant mark labeled with a (typographic) prime symbol on slide rule calculating devices in the 20th century. The Pickworth reference explains its use for sines and tangents of small angles.

Examples

			3437.7467707849392526078892888463102199443283479938592929496...
		

References

  • C. N. Pickworth, The Slide Rule, 24th Ed., Pitman, London, 1945, pp. 76-78, Trigonometrical Applications.

Crossrefs

Programs

  • Mathematica
    RealDigits[10800/Pi, 10, 100][[1]] (* Amiram Eldar, Sep 18 2020 *)

Formula

Equals 60 * A072097.
Showing 1-2 of 2 results.