OFFSET
0,1
LINKS
FORMULA
a(n) = 2*Sum_{k= 1,2,3,4..n} A213544(k).
EXAMPLE
For n=4, the unreduced mediants are 1/2, 2/4, 5/10, 9/18, hence the sum of denominators is 2+4+10+18 = 34.
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Nehul Yadav, Oct 15 2014
STATUS
approved