OFFSET
0,2
EXAMPLE
a(5) = 10+mu(4) = (9+1)+0 = (6+3)+1+0 = (2+4)+4+0 = (-1+3)+8+0 = mu(5)+a(4)+8+mu(4).
PROG
(Python)
from itertools import count, islice, accumulate
from sympy import mobius
def A061531_gen(): # generator of terms
blist, m = tuple(), 1
for i in count(1):
yield (blist := tuple(accumulate(reversed(blist), initial=m)))[-1]
m = mobius(i)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Frank Ellermann, Jun 13 2001
STATUS
approved