129076

Appears in sequences

• Indices of records in A157190: prime(a(n)) can be written in more ways as pq-p-q (p,q, prime) than any smaller prime.at n=14A157191
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k increasing cycles of length >=2 (0<=k<= n/2). A cycle (b(1), b(2), ...) is said to be increasing if, when written with its smallest element in the first position, it satisfies b(1) < b(2) < b(3) < ... .at n=26A186757
• Triangle read by rows, T(n,k) = Sum_{j=0..k-1} S(n,j+1)*S(n,k-j) where S denotes the Stirling cycle numbers A132393, T(0,0)=1, n>=0, 0<=k<=2n-1.at n=34A254882
• a(n) = (n!)^2 * Sum_{k=1..n} binomial(n,k) / k^2.at n=4A294117
• Irregular triangle read by rows. Coefficients of the polynomials (-1)^n*binomial(-x - 1, -x - n - 1) * binomial(n + x, x) * (n!)^2 in ascending order of powers.at n=27A358501