472500

Appears in sequences

• sec(log(x+1)-arctanh(x))=1+3/4!*x^4+90/6!*x^6+5145/8!*x^8...at n=5A013303
• Primal codes of canonical finite permutations on positive integers.at n=20A109299
• Triangle read by rows: terms T(n,k) of a binomial decomposition of n as Sum(k=0..n)T(n,k).at n=33A244131
• From higher-order arithmetic progressions: Erroneous version of A378234.at n=2A259461
• Bi-unitary harmonic numbers.at n=38A286325
• a(n) = Product_{d|n, d<n} A019565(phi(d)), where phi is the Euler totient function A000010.at n=55A318834
• Triangle read by rows: T(n, k) = binomial(n - 1, k - 1) * (k - 1)^(k - 1) * (n - k) * (n - k + 1)^(n - k - 1).at n=40A369016
• Triangle read by rows: T(n, k) = binomial(n-1, k-1) * (k - 1)^(k - 1) * k * (n - k + 1)^(n - k - 1).at n=40A369017
• From higher-order arithmetic progressions: Corrected version of A259461.at n=2A378234