24228

Appears in sequences

• Even numbers of the form floor( binomial(2k, 2j)/binomial(k, j)).at n=15A111304
• Numbers n with property that average digit of n^2 is s=7.at n=28A164773
• The number of steps for a knight to be trapped when moving on a spirally numbered hexagonal board to the lowest available unvisited cell and starting at cell n.at n=16A333683
• G.f. A(x) satisfies: A(x) = x + x^3 * exp(A(x) + A(x^2)/2 + A(x^3)/3 + A(x^4)/4 + ...).at n=24A346020
• Number of Gray code sequences of length 2*n where numbers are between 0 and 2*n-1.at n=10A350784
• a(n) = binomial(2*n-1,n) - n^2 - 1.at n=6A359435
• a(n) = Sum_{k=1..n-1} tau(k) * sigma_2(n-k).at n=27A374973
• Square array A(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where column k is the expansion of e.g.f. B(x)^k, where B(x) is the e.g.f. of A213109.at n=41A384802