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1,2
This is the arithmetic-geometric mean of 1 and 2, given by u(1)=1, v(1)=2, u(n+1)=(u(n)+v(n))/2, v(n+1)=sqrt(u(n)*v(n)); agm(1;2)=lim u(n)=lim v(n).
Ivan Panchenko, Table of n, a(n) for n = 1..1000
Eric Weisstein's World of Mathematics, Arithmetic-Geometric Mean
1.45679103...
RealDigits[ ArithmeticGeometricMean[1, 2], 10, 105] // First (* Jean-François Alcover, Feb 06 2013 *)
Sequence in context: A140293 A075341 A143789 * A196697 A068318 A242337
Adjacent sequences: A068518 A068519 A068520 * A068522 A068523 A068524
easy,nonn,cons
Benoit Cloitre, Mar 21 2002
approved