843314857domain: NAppears in sequencesa(n) = round(Pi*2^(n-1)) for n >= 1, a(0) = 1.at n=29A121349Nearest integer to 2^n*Pi/4.at n=30A155996Least integer k such that k/2^n > Pi.at n=28A293342a(n) = ceiling((16^n)*Sum_{k=0..n+1} (4/(8k+1)-2/(8k+4)-1/(8k+5)-1/(8k+6))/16^k).at n=7A343572