OFFSET
1,2
EXAMPLE
For n = 3, a(3) = binomial(prime(3),prime(1)) + binomial(prime(3),prime(2)) = binomial(5,2) + binomial(5,3) = 10 + 10 = 20.
MATHEMATICA
Table[Sum[Binomial[Prime[n], Prime[i]], {i, n-1}], {n, 25}] (* Paolo Xausa, Jun 29 2024 *)
PROG
(Python)
from sympy import binomial
from sympy import prime
def a(n): return sum(binomial(prime(n), prime(i)) for i in range(1, n))
print([a(n) for n in range(1, 22)])
(PARI) a(n) = sum(i=1, n-1, binomial(prime(n), prime(i))); \\ Michel Marcus, Jun 25 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Alexandre Herrera, Jun 06 2024
STATUS
approved