OFFSET
0,5
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..2000
EXAMPLE
a(4) = 5 enumerates these subsets: {1}, {4}, {1,4}, {1,2,4}, {1,3,4}.
MAPLE
b:= proc(n, t) option remember; `if`(n=0, `if`(t<0, 1, 0),
b(n-1, t)+b(n-1, t+`if`(isprime(n), 1, -1)))
end:
a:= n-> b(n, 0):
seq(a(n), n=0..34); # Alois P. Heinz, Feb 03 2024
MATHEMATICA
Map[Length[Select[Map[Commonest, PrimeQ[Rest[Subsets[Range[#]]]]], # == {False, True} || # == {True, False} &]] &, Range[22]] (* Peter J. C. Moses, Jan 29 2024 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Feb 03 2024
EXTENSIONS
a(23)-a(34) from Alois P. Heinz, Feb 03 2024
STATUS
approved