203904

Appears in sequences

• E.g.f. tan(tan(x)), zeros omitted.at n=4A003718
• a(n) = Sum_{k=0..n} binomial(2^(n-k) + k, n-k).at n=5A136507
• Array A(i,j) read by antidiagonals: A(i,j) is the (2*i-1)-th derivative of tan(tan(tan(...tan(x)))) nested j times evaluated at 0.at n=19A212267
• The number of positive integer sequences of length n with no duplicate substrings (forward or backward) of length greater than 1 and a minimal sum (= A282168(n)).at n=16A284432