OFFSET
0,2
COMMENTS
See A210000 for a guide to related sequences.
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..1000
FORMULA
From Andrew Howroyd, May 05 2020: (Start)
a(n) = -12 + 32*Sum_{k=1..n} phi(k) for n > 0. (End)
MATHEMATICA
(See the Mathematica section at A209981.)
PROG
(PARI) a(n)=if(n<1, 0, 32*sum(k=1, n, eulerphi(k)) - 12) \\ Andrew Howroyd, May 05 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Mar 17 2012
STATUS
approved