91648

Appears in sequences

• Number of subsets of integers 1 through n (including the empty set) containing no pair of integers that share a common factor.at n=36A084422
• Expansion of 1/(1-4x-4x^3).at n=8A089979
• Number of subsets of {1, 2, ..., n} containing n and having pairwise coprime elements; also row sums of A186972.at n=36A186973
• Number of permutations of length n containing exactly 1 occurrence of 123 and 2 occurrences of 132.at n=13A224289
• Number of (n+2) X (7+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 2 3 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 2 3 6 or 7.at n=7A252531
• Numbers whose prime indices and prime signature have the same mean.at n=41A359903
• Strongly 2-near perfect numbers.at n=4A366172