def sums(n):
return sum(numbertheory.fib(6*n+3)//2 for n in range(1, n + 1))
def A3(n):
#return sum(fib(4*i+2) for i in range((n+1)//2)) + fib(2*n+1) - 1
if n < 1:
return 0
m = n + (n%2)
return fib(m-1)*fib(m+1) + fib(2*n+1) - 2
def sol3(n):
if n % 2 == 0:
return 7*(fib(2*n+2) - n - 1)//5
return (8*fib(2*n+2) - 7*n - 7)//5
def A1(n):
return sum(fib(4*i+2) for i in range((n+1)//2)) + sum(fib(2*i) for i in range(1, n+1))
