9979200

Appears in sequences

• -arctan(log(x+1)-arctanh(x))=1/2!*x^2+6/4!*x^4+90/6!*x^6+2520/8!*x^8...at n=6A013297
• a(n) = Product_{k=1..n} rad(k), where rad(n) is the product of distinct prime factors of n, cf. A007947.at n=12A048803
• Number of labeled cyclic groups with a fixed identity.at n=11A058161
• Number of degree-n odd permutations of order exactly 8.at n=12A061140
• The n-digit number whose divisors have the maximal sum (A066410).at n=6A066424
• a(n) = Product_{i=1..n} (2*n-i)*(2*n+i).at n=3A093434
• a(n) = meantorial(n) = the product of the set of n closest numbers with an arithmetic mean of n.at n=7A110347
• a(n) = denominator of b(n), where b(1) = 1, b(n) = Sum_{k=1..n-1} b(n-k) * H(k); H(k) = Sum_{j=1..k} 1/j, the k-th harmonic number.at n=12A128045
• a(n) = denominator of b(n), where b(1)=1, b(n+1) = sum{k=1 to n} {b(n+1-k)/k} ({x} is the fractional part of x).at n=12A128192
• a(2) = 1, a(3)=3; for n >= 4, a(n) = (n-2)!*Stirling_2(n,n-1)/2 = n!/4.at n=9A133799
• Degree of Lagrange resolvent of polynomial of composite degree.at n=6A137150
• Small factors of some highly composite numbers.at n=22A161894
• Small factors of some highly composite numbers.at n=23A161894
• Triangle read by rows: T[n,m] = quadruple factorials A001813(n) * binomials A007318(n,m).at n=25A164961
• Triangle read by rows: T[n,m] = quadruple factorials A001813(n) * binomials A007318(n,m).at n=23A164961
• Number of multiset permutations of the n initial elements of A005229 with additional element A005229(0)=1.at n=11A169638
• Number of permutations of 1..n with the sequence of sums of 9 adjacent elements having exactly 2 maxima.at n=1A179737
• Triangle of the value of Bell polynomials of the second kind B(n,m)(6,30,120,360,720,720) in row n, column m.at n=29A188062
• Product of the radicals of the integers less than n and relatively prime to n.at n=12A220271
• Number of n-length words w over an 8-ary alphabet {a1,a2,...,a8} such that #(w,a1) >= #(w,a2) >= ... >= #(w,a8) >= 1, where #(w,x) counts the letters x in word w.at n=3A226887