OFFSET
0,3
FORMULA
a(n) = 2^n - A065795(n). - Alois P. Heinz, Sep 13 2019
EXAMPLE
The a(1) = 1 through a(5) = 22 subsets:
{} {} {} {} {}
{1,2} {1,2} {1,2} {1,2}
{1,3} {1,3} {1,3}
{2,3} {1,4} {1,4}
{2,3} {1,5}
{2,4} {2,3}
{3,4} {2,4}
{1,2,4} {2,5}
{1,3,4} {3,4}
{1,2,3,4} {3,5}
{4,5}
{1,2,4}
{1,2,5}
{1,3,4}
{1,4,5}
{2,3,5}
{2,4,5}
{1,2,3,4}
{1,2,3,5}
{1,2,4,5}
{1,3,4,5}
{2,3,4,5}
MATHEMATICA
Table[Length[Select[Subsets[Range[n]], !MemberQ[#, Mean[#]]&]], {n, 0, 10}]
PROG
(Python)
from sympy import totient, divisors
def A327471(n): return (1<<n)-(sum((sum(totient(d)<<k//d-1 for d in divisors(k>>(~k&k-1).bit_length(), generator=True))<<1)//k for k in range(1, n+1))>>1) # Chai Wah Wu, Feb 22 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, Sep 12 2019
EXTENSIONS
More terms from Alois P. Heinz, Sep 13 2019
STATUS
approved