70216

Appears in sequences

• a(1)=1. a(n) = sum of earlier terms, a(k) (1<=k<=n-1), where gcd(a(k),n) is squarefree.at n=21A122169
• Sum of binary palindromes p < 2^n.at n=11A206918
• Number of n X 7 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 1 0 vertically.at n=3A208286
• T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 1 0 vertically.at n=48A208287
• Number of 4 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 1 0 vertically.at n=6A208288
• Number of cyclic subgroups of the group C_n x C_n x C_n x C_n, where C_n is the cyclic group of order n.at n=31A280184
• a(n) = Sum_{k=1..n} gcd(k, n)^4.at n=15A343498
• a(n) is the number of negative Euler permutations of order n.at n=9A347602