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.

A213201 Mean of leading digits in real-life sources of data, according to Benford's law (also called the first-digit law).

Original entry on oeis.org

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

Views

Author

Joost de Winter, Mar 01 2013

Keywords

Examples

			3.44023696712320624882523876...
		

References

  • Scott, P., and Fasli, M. (2001). Benford's law: An empirical investigation and a novel explanation. Unpublished Manuscript.

Programs

  • MATLAB
    digits(100);clear R;for i=1:9;R(i)=vpa([num2str(i) '*log10(1+1/' num2str(i) ')']);end;sum(R)
    
  • MATLAB
    vpa('2*log10(2)-4*log10(3)+8*log10(5)-log10(7)')
    
  • Mathematica
    RealDigits[Log[10, 1562500/567], 10, 105][[1]] (* Jean-François Alcover, Nov 28 2018 *)
  • PARI
    sum(d=1, 9, d*log(1+1/d)/log(10)) \\ Michel Marcus, Nov 28 2018

Formula

Equals Sum_{d=1..9} d*log(1+1/d)/log(10).