23703

Appears in sequences

• Triangle, read by rows, T(n,k) = (k+1)*Sum_{i=0..n-k} C(k+2*i,i)*C(n-i-1,n-k-i)/(k+i+1).at n=57A247582
• Least hairpin family matchings with n edges that are both L&P and C&C whose leftmost edge is part of a hairpin.at n=9A284968
• Number of nonisomorphic magmas with n elements satisfying the equation x(yz) = xz.at n=6A362384
• Triangular array T(n,k), read by rows: coefficients of strong divisibility sequence of polynomials p(1,x) = 1, p(2,x) = 1 + 5x, p(n,x) = u*p(n-1,x) + v*p(n-2,x) for n >=3, where u = p(2,x), v = 1 - x - x^2.at n=39A367210