OFFSET
0,8
FORMULA
G.f.: (1/2) * (1 / (1 - Sum_{k>=1} x^prime(k)) - 1 / (1 + Sum_{k>=1} x^prime(k))).
EXAMPLE
a(8) = 3 because we have [3, 3, 2], [3, 2, 3] and [2, 3, 3].
MAPLE
b:= proc(n, t) option remember; `if`(n=0, t, add(
b(n-ithprime(j), 1-t), j=1..numtheory[pi](n)))
end:
a:= n-> b(n, 0):
seq(a(n), n=0..55); # Alois P. Heinz, Dec 03 2020
MATHEMATICA
nmax = 47; CoefficientList[Series[(1/2) (1/(1 - Sum[x^Prime[k], {k, 1, nmax}]) - 1/(1 + Sum[x^Prime[k], {k, 1, nmax}])), {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Dec 03 2020
STATUS
approved