23086

Appears in sequences

• n! has a palindromic prime number of digits.at n=31A035067
• Integers n > 10553 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 10553.at n=21A063061
• Solutions to phi(x + omega(x)) = phi(x) + d(x), where phi() = A000010(), d() = A000005() and omega() = A001221().at n=6A063868
• Diagonal in array of n-gonal numbers A081422.at n=27A081438
• 63-gonal numbers: a(n) = n*(61*n - 59)/2.at n=28A098140
• P(P(n))-P(P(n-1)), where P(n) = n(n+1)(n+2)/6 (cf. A000292).at n=6A113596
• Triangle T(n,k) read by rows: T(n, k) = (m*n - m*k + 1)*T(n - 1, k - 1) + (9*k - 8)*(m*k - (m - 1))*T(n - 1, k) where m = 0.at n=42A166979
• Number of n element 1..n arrays with each element the minimum of 3 adjacent elements of a permutation of 1..n+2 of n+2 elements.at n=7A217886
• T(n,k) is the number of n element 1..n arrays with each element the minimum of k adjacent elements of a permutation of 1..n+k-1 of n+k-1 elements.at n=52A217891
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 205", based on the 5-celled von Neumann neighborhood.at n=32A270731
• a(n) = number of subsets S of {1,2,...,n} having more than 2 elements such that (sum of least three elements of S) > max(S).at n=17A357289