OFFSET
0,9
FORMULA
EXAMPLE
For a(7)=1, the chiral pair is 0001011-0001101. For a(8)=2, the chiral pairs are 00001011-00001101 and 00010011-00011001.
MATHEMATICA
Join[{0}, Table[(DivisorSum[NestWhile[#/2 &, n, EvenQ], MoebiusMu[#] 2^(n/#) &]/(2 n) - DivisorSum[n, MoebiusMu[n/#] 2^Floor[#/2] &])/2, {n, 1, 40}]]
PROG
(PARI) a(n) = if (n, (sumdiv(n, d, if (d%2, moebius(d)*2^(n/d)))/(2*n) - sumdiv(n, d, moebius(n/d)*2^(d\2)))/2, 0); \\ Michel Marcus, Jun 27 2019; corrected Jun 12 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert A. Russell, Jun 18 2019
STATUS
approved