123760

Appears in sequences

• a(n) = (n-1)*(2*n-1)*(3*n-1)*(4*n-1).at n=9A033593
• a(n) = Product_{k=1..n} (9*k - 1); 9-factorial numbers.at n=4A049211
• G.f.: 1/((1-x^2)^3*(1-x)^4).at n=25A060099
• Triangle read by rows: T(n,k) is the number of dissections of a convex n-gon by nonintersecting diagonals, having exactly k triangles (n >= 2, k >= 0).at n=61A090985
• Nonuple factorial, 9-factorial, n!9, n!!!!!!!!!.at n=35A114806
• Numbers k not divisible by 6 such that sigma(k) > 3*k.at n=7A126104
• a(n) = (prime(n)^5 - prime(n))/3.at n=5A138425
• Triangle sequence: T(n, k) = -Product_{j=0..k+1} ((n+1)*j - 1).at n=39A153187
• Triangle read by rows: T(n,k) = Product_{i=0..k-2} (i*n + n - 1).at n=31A153273
• Triangle read by rows: T(n,k) is the number of weighted lattice paths B(n) having k uHd strings.at n=43A247292
• a(n) = lcm{1,2,...,n} / binomial(n,floor(n/2)).at n=33A263673
• Number of different 3 against 3 matches given n players.at n=17A271040
• a(n) = denominator of Sum_{k=2..A335138(n)} abs(A309229(n, k))/k.at n=32A335417
• Number of ways to write n as an ordered sum of 7 primes (counting 1 as a prime).at n=40A341986
• T(n, k) = (n + k - 1)*(n + k)*binomial(2*n + 1, n - k + 1) with T(0, 0) = T(1, 0) = 1. Triangle read by rows, T(n, k) for 0 <= k <= n.at n=42A342313
• a(n) is the number of "merger histories" of n elements (see A256006) where at most 3 elements can merge at the same time.at n=6A358072
• Triangle read by rows. T(n, k) = (1/2) * C(n, k) * C(3*n - 1, n) for n > 0 and T(0, 0) = 1.at n=24A360560
• Denominator of Sum_{1<=j<=k<=n, gcd(j,k)=1} 1/(j*k).at n=17A365228
• Denominators of the partial sums of the reciprocals of the sum of unitary divisors function (A034448).at n=30A379514
• Pisano period of Hexanacci numbers (A001592) mod n.at n=38A381508