login
a(n) = A086330(prime(n)).
1

%I #48 Apr 17 2024 02:20:39

%S 0,2,7,18,43,73,113,159,203,334,496,706,863,874,1097,1124,1560,2033,

%T 2073,2409,2462,3336,3345,3634,3958,4657,5198,5284,5186,6096,7801,

%U 8594,9270,9167,10659,10578,12375,12227,13221,13769,15958,16458,18820,17919,18722

%N a(n) = A086330(prime(n)).

%C The sequence sometimes decreases, as for example at a(29) = 5186 < 5284 = a(28).

%e For n = 3, a(n) = A086330(prime(3)) = A086330(5) = (2! mod 5) + (3! mod 5) + (4! mod 5) = 2 + 1 + 4 = 7.

%o (Python)

%o from sympy import isprime

%o l = []

%o for i in range(2,185):

%o if isprime(i):

%o sum = 0

%o reminder = 1

%o for j in range(2, i):

%o reminder = (reminder * j) % i

%o sum += reminder

%o l.append(sum)

%o print(l)

%o (Python)

%o from sympy import prime

%o def A371035(n):

%o a, c, p = 0, 1, prime(n)

%o for m in range(2,p):

%o c = c*m%p

%o a += c

%o return a # _Chai Wah Wu_, Apr 16 2024

%o (PARI) a(n) = my(p=prime(n)); sum(m=2, p, m! % p); \\ _Michel Marcus_, Apr 11 2024

%Y Cf. A086330, A000040.

%K easy,nonn

%O 1,2

%A _Alexandre Herrera_, Apr 10 2024