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.

A016650 Decimal expansion of log(27).

Original entry on oeis.org

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

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Keywords

Examples

			3.295836866004329074185735710767577113942471673468248355204083000912482... - _Harry J. Smith_, May 20 2009
		

References

  • M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 2.

Crossrefs

Cf. A016455 (continued fraction).

Programs

  • Mathematica
    RealDigits[Log[27],10,120][[1]] (* Harvey P. Dale, May 07 2012 *)
  • PARI
    default(realprecision, 20080); x=log(27); for (n=1, 20000, d=floor(x); x=(x-d)*10; write("b016650.txt", n, " ", d)); \\ Harry J. Smith, May 20 2009

Formula

Log(27) = Integral_{x = 0..oo} sin(4*x)^3/x^2 dx. - Peter Bala, Nov 04 2019
From Peter Bala, Feb 27 2024: (Start)
Equals 4 - 2*Sum_{k >= 0} 1/((2*k + 1)*(2*k + 3)*4^k).
Continued fraction: 4 - 16/(24 - 96/(84 - 1440/(186 - ... - 16*n*(n + 1)(4*n^2 - 1)/((2*(n + 1)*(10*n + 11)) - ... )))). (End)
Equals 3*A002391. - R. J. Mathar, Jul 22 2025