40168

Appears in sequences

• Given the infinite continued fraction (1+i)+((1+i)/(1+i)+((1+i)/((1+i)+...)))), where i is the square root of (-1), this is the numerator of the real part of the convergents.at n=10A093725
• Numbers k such that 5*10^k - 9 is prime.at n=18A103001
• Number of ways to place 4 nonattacking zebras on a 4 X n board.at n=8A172222
• Number of permutations of 1..n avoiding adjacent step pattern up, up, up, up, up.at n=8A177533
• a(n+5) = a(n+4)+a(n+3)+a(n+2)+a(n+1)+2*a(n) with a(0)=2, a(1)=1, a(2)=5, a(3)=10, a(4)=20.at n=15A226311
• Second differences of the overpartitions.at n=37A361298