Wikipedia:Reference desk/Archives/Mathematics/2013 February 9

= February 9 =

significance of a series
what is the significance of the series 1, 1, 1, 1, 1, 1, etc. Does it have any special properties? This is A000012 in the online integers database. — Preceding unsigned comment added by 178.48.114.143 (talk) 06:17, 9 February 2013 (UTC)


 * The OEIS entry for lists many properties of this sequence. —Bkell (talk) 18:45, 9 February 2013 (UTC)

For my sandbox
Can somebody calculate the midway point between 500 and 2,200,000,000 please? Please show the calculation as well. This is for a wiki-essay to calculate the largest and smallest religious populations, 2.2 billion being Christians. Thanks Pass a Method   talk  20:34, 9 February 2013 (UTC)


 * What you want is the arithmetic mean, in your case


 * $${500 + 2,200,000,000 \over 2}$$


 * See also http://www.freemathhelp.com/arithmetic-mean.html for some illustrative examples. You might also want to take a look at midpoint. The midpoint is just a special case of an arithmetic mean where you have two terms. --  Toshio   Yamaguchi  20:57, 9 February 2013 (UTC)


 * For something like this I think the geometric mean is more appropriate. For these values you get


 * $$\sqrt{500 * 2200000000} = 1048809$$


 * In other words, about a million. Looie496 (talk) 00:30, 10 February 2013 (UTC)