50138domain: NAppears in sequencesa(n) = floor(exp(n/Pi)).at n=33A062121Number of n-digit base-7 deletable primes.at n=9A096240Start of a triple of consecutive squarefree numbers each of which has exactly 4 distinct prime factors.at n=4A242607a(n) = Sum_{k=0..floor(n/4)} binomial(n-3*k,k) * binomial(2*(n-4*k),n-4*k).at n=9A383582