42857

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 = (Fibonacci numbers), t = (composite numbers).at n=28A024461
• a(n) = smallest k such that the digit sum of 7k is n.at n=45A077494
• Structured triakis icosahedral numbers (vertex structure 4).at n=16A100172
• G.f. satisfies: A(x) = x/(x - B(x^2)) where B(x/A(x)) = x and B(x) is the g.f. of A141200.at n=18A178852
• a(n) = floor(((n mod 6)+1) * 10^floor((n/6)+1) / 7).at n=26A343915