35621

Appears in sequences

• n-th 6k+1 prime times n-th 6k-1 prime.at n=20A048629
• Sum_{k<=n} (sigma(k)^2), where sigma(k) denotes the sum of the divisors of k A000203.at n=32A072379
• Brilliant numbers k such that 2k+1 is also brilliant.at n=20A085649
• a(n) = numerator(6 * Sum_{k=2..n} 1/(binomial(2*k, k)*(k-1))).at n=6A145566
• Triangle read by rows: T(n,k) is the number of permutations of [n] having k adjacent transpositions (0 <= k <= floor(n/2)). An adjacent transposition is a cycle of the form (i, i+1).at n=20A177248
• Number of permutations of [n] having no adjacent transpositions, that is, no cycles of the form (i, i+1).at n=8A177249
• Number of symmetrically unique Dyck paths of semilength n and height three.at n=10A291887
• Number of increasing interval-labeled restricted ternary trees on the label set {0,1,...,n}.at n=7A390399