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 1-4 of 4 results.

A100668 Decimal expansion of the base-2 analog of the Euler-Mascheroni constant.

Original entry on oeis.org

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

Views

Author

Joseph Biberstine (jrbibers(AT)indiana.edu), Dec 05 2004

Keywords

Examples

			0.83274617727686715064641751940811553516243153102632810163149819758458\ 1351446095842290202600344430630467860292319092706478030883524064025...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Limit[Sum[D[Log[2, x], x] /. x -> k, {k, 1, n}] - Log[2, n], n -> Infinity], 10, 135][[1]]
  • PARI
    Euler/log(2) \\ Michel Marcus, Jun 02 2020

Formula

EulerGamma/log(2) = A001620/A002162.
Equals Integral_{x=-infinity..infinity} x*2^(-x)*log(2)*exp(-2^(-x)) dx. - Alois P. Heinz, Nov 09 2016

A158469 Continued fraction for hz = limit_{k -> infinity} 1 + k - Sum_{j = -k..k} exp(-2^j).

Original entry on oeis.org

1, 3, 189, 3, 2, 2, 1, 5, 4, 1, 1, 3, 1, 1, 1, 5, 8, 12, 1, 22, 7, 14, 1, 2, 1, 5, 1, 4, 222, 1, 1, 2, 3, 24, 6, 27, 1, 15, 1, 9, 1, 1, 18, 6, 24, 2, 1, 7, 1, 4, 2, 2, 1, 1, 84, 1, 1, 1, 3, 1, 1, 1, 1, 1, 5, 15, 3, 13, 3, 2, 14, 1, 1, 1, 10, 15, 10, 1, 6, 120, 1, 31, 2, 4, 2, 7, 2, 2, 1, 1, 1, 1, 1, 3, 7
Offset: 0

Views

Author

Alois P. Heinz, Mar 19 2009

Keywords

Examples

			1.33274738243289922500860109837389970441674398225984453657972 ...
		

Crossrefs

Cf. A158468 (decimal expansion), A159835 (Engel expansion).

Programs

  • Maple
    with(numtheory): hz:= limit(1+k -sum(exp(-2^j), j=-k..k), k=infinity): cfrac(evalf(hz, 130), 100, 'quotients')[];
  • Mathematica
    terms = 95; digits = terms+15; Clear[f]; f[k_] := f[k] = 1+k-Sum[Exp[-2^j], {j, -k, k}] // RealDigits[#, 10, digits+1]& // First // Quiet; f[1]; f[n = 2]; While[f[n] != f[n-1], n++]; hz = FromDigits[f[n]]*10^-digits; ContinuedFraction[hz, terms] (* Jean-François Alcover, Mar 23 2017 *)

A159835 Engel expansion of hz = limit_{k -> infinity} 1 + k - Sum_{j = -k..k} exp(-2^j).

Original entry on oeis.org

1, 4, 4, 4, 4, 6, 11, 11, 11, 14, 61, 266, 1006, 1030, 1261, 6264, 7583, 7979, 7986, 12386, 80041, 87434, 130927, 270073, 1653819, 1715177, 1973657, 3483485, 12346987, 17531499, 21237674, 84103203, 195088616, 725688944, 2813572082, 3138084145, 10870485195
Offset: 1

Views

Author

Alois P. Heinz, Apr 23 2009

Keywords

Comments

Cf. A006784 for definition of Engel expansion.

Examples

			hz = 1.3327473824328992250086010983738997044167439822598445365797 ...
		

References

  • F. Engel, Entwicklung der Zahlen nach Stammbrüchen, Verhandlungen der 52. Versammlung deutscher Philologen und Schulmänner in Marburg, 1913, pp. 190-191.

Crossrefs

Cf. A158468 (decimal expansion), A158469 (continued fraction).

Programs

  • Maple
    hz:= limit(1+k -sum(exp(-2^j), j=-k..k), k=infinity):
    engel:= (r,n)-> `if`(n=0 or r=0, NULL, [ceil(1/r), engel(r*ceil(1/r)-1, n-1)][]):
    Digits:=300:
    engel(evalf(hz), 39);

Extensions

Some terms corrected by Alois P. Heinz, Nov 22 2020

A339168 Decimal expansion of Sum_{k>=1} Im(Gamma(1-2*k*Pi*i/log(2)))/(k*Pi).

Original entry on oeis.org

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

Views

Author

Alois P. Heinz, Nov 25 2020

Keywords

Examples

			0.00000120515603207436218357896578416925431245123351643494822...
		

Crossrefs

Programs

  • Maple
    evalf(sum(Im(GAMMA(1-2*k*Pi*I/log(2)))/(k*Pi), k=1..infinity), 120);

Formula

Equals A158468 - gamma/log(2) - 1/2.
Showing 1-4 of 4 results.