OFFSET
0,2
COMMENTS
a(n) = sum of n-th row of the triangle formed by replacing each m in Pascal's triangle by phi(m). See A102715.
LINKS
Harry J. Smith, Table of n, a(n) for n = 0..200
EXAMPLE
For n=4, the binomial coefficients C(4,j) are 1, 4, 6, 4, and 1. The totients are 1, 2, 2, 2, and 1. So a(4) = 1 + 2 + 2 + 2 + 1 = 8. - Michael B. Porter, Jun 25 2018
MATHEMATICA
a(n)=Apply[Plus, Table[EulerPhi[Binomial[n, w]], {w, 0, n}]],
PROG
(PARI) a(n) = vecsum(vector(n+1, k, eulerphi(binomial(n, k-1)))); \\ Michel Marcus, Jun 24 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Oct 02 2001
STATUS
approved