1381380

Appears in sequences

• T(2n,n), array T given by A047000.at n=10A047009
• a(n) = 1/(Integral_{x=0..1} (x^4 - x^5)^n dx).at n=5A090957
• G.f. satisfies: A(x) = x/series_reversion(x/G(x)) where A(x) + A(-x) = 2*G(x^2) and G(x) is the g.f. of A046646.at n=19A116637
• Numbers that are divisible by exactly 7 distinct primes.at n=21A176655
• Numbers with prime factorization pqrstuv^2.at n=2A190381
• Triangle read by rows: the reversed x = 1+q Narayana triangle at m=2.at n=49A243662
• Number T(n,k) of 2n-length strings of balanced parentheses of exactly k different types that are introduced in ascending order; triangle T(n,k), n>=0, 0<=k<=n, read by rows.at n=39A253180
• a(n) = 6*binomial(n+1, 6).at n=20A253946
• Number of 2n-length strings of balanced parentheses of exactly 3 different types that are introduced in ascending order.at n=5A258391
• a(1) = 0; for n > 1, a(n) = Product_{d|n, 1 < d < n} prime(A305788(d)-1).at n=47A305812
• Numbers with a record number of distinct values of the unitary totient function applied to their unitary divisors (A348001).at n=14A348002
• Triangle read by rows: T(n,k) = binomial(n+1,k+1) * binomial(5*n-4*k+1,k) / (n+1), 0<=k<=n.at n=50A391048