1891890

Appears in sequences

• Triangle read by rows: T(0,0) = 1, T(n,k) = Sum_{j=max(0,1-k)..n-k} (2^j)*(binomial(k+j,1+j) + binomial(k+j+1,1+j))*T(n-1,k-1+j).at n=26A085734
• T(n, k) = [x^k] (2*n)! [z^(2*n)] 1/cos(z)^x, triangle read by rows, for 0 <= k <= n.at n=34A088874
• a(n) = sum of numbers which in base 2 contain exactly n digits 1 and not more than n digits 0.at n=6A131568
• Triangle read by rows: T(n,k) is the number of end rhyme patterns of a poem of an even number of lines (2n) with 1<=k<=n evenly rhymed sounds.at n=25A156289
• Largest solution to phi(x) = n!, where phi() is Euler totient function (A000010).at n=8A165774
• a(n) is the sum of the first A179859(n) noncomposites.at n=5A179861
• A double factorial triangle.at n=38A193229
• Triangle S(n, k) by rows: coefficients of 2^(n/2)*(x^(1/2)*d/dx)^n, where n =0, 2, 4, 6, ...at n=29A223524
• Triangle read by rows: T(n,k) (n>=2, 1<=k<=n-1) is the number of unordered pairs of vertices at distances k in the odd graph O_n.at n=24A228308
• Table read by rows, T(n, k) = Y(2*n, k, Z(2*n - k)) where Y are the partial Bell polynomials and Z(m) is the list [A126869(j), j=-1..2*m].at n=34A350463
• T(n, k) = [x^k] (1/2 - x)^(-n) - (1 - x)^(-n).at n=27A356117
• T(n, k) = [x^k] (1/2 - x)^(-n) - (1 - x)^(-n).at n=33A356117