19148

Appears in sequences

• a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (odd natural numbers), t = (primes).at n=30A024603
• Least k such that decimal representation of k*n contains only digits 0 and 4.at n=22A096683
• Least k such that decimal representation of k*n contains only digits 0 and 8.at n=45A096687
• a(0)=1 and a(n) for n > 0 equals the minimal positive integer such that addition of 2^(-a(n)) to Sum_{k = 0,1,...,n-1} 2^(-a(k)) changes only trailing zeros in its decimal representation.at n=8A137284
• a(n) = permanent M_n where M_n is the n X n matrix m(i,j) = Catalan(i+j).at n=3A278843
• a(n) = 1 + Sum_{k=0..n-5} a(k) * a(n-k-5).at n=29A346074
• Expansion of 1 / (1 + Sum_{k>=1}(-x)^Lucas(k)).at n=35A357384
• Array read by ascending antidiagonals: A(n, k) is the permanent of the n-th order Hankel matrix of Catalan numbers M(n) whose generic element is given by M(i,j) = A000108(i+j+k) with i,j = 0, ..., n-1.at n=17A368026