OFFSET
1,2
COMMENTS
n is in this sequence if and only if sum_{k=1..n} (n-k|k) = sum_{k=1..n} |(n-k|k)|.
MATHEMATICA
Reap[ Do[ If[ Sum[ KroneckerSymbol[n - k, k], {k, 1, n}] == EulerPhi[n], Print[n]; Sow[n]], {n, 1, 8000}]][[2, 1]] (* Jean-François Alcover, Jul 29 2013 *)
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Luschny, Aug 07 2012
STATUS
approved