import sys
input = sys.stdin.readline

N=int(input())
A=list(map(int,input().split()))
mod=10**9+7


DP=[[0]*(N+1) for i in range(101)]
DP[0][0]=1

for i in range(N):
    a=A[i]
    for j in range(1,101):
        if i-j>=0:
            DP[j][i]+=DP[j][i-j]
            DP[j][i]%=mod

            DP[0][i]+=DP[j][i]
            DP[0][i]%=mod
            
    if a>100:
        for j in range(i+a,N,a):
            DP[0][j]+=DP[0][i]

    else:
        DP[a][i]+=DP[0][i]
        DP[a][i]%=mod

    if a!=1:
        DP[0][i+1]+=DP[0][i]
        DP[0][i+1]%=mod

print(DP[0][N-1])