163840

Appears in sequences

• a(n) = 10*4^n.at n=7A002066
• a(n) = 5 * 2^n.at n=15A020714
• Numbers of form 4^i*10^j, with i, j >= 0.at n=30A025621
• Numbers of form 5^i*8^j, with i, j >= 0.at n=28A025623
• Expansion of (1 + 2x + 6x^2 + x^3)/(1 - 2x^2).at n=33A029745
• Numbers of the form 2^k times 1, 3 or 5.at n=49A029747
• a(n) = n*8^n.at n=5A036294
• Triangle whose (i,j)-th entry is binomial(i,j)*8^(i-j)*8^j.at n=16A038286
• Triangle whose (i,j)-th entry is binomial(i,j)*8^(i-j)*8^j.at n=19A038286
• First differences of A045623.at n=16A045891
• Numbers k such that d(k)^3 divides k.at n=8A046755
• Numbers n such that n+cototient(n) is a power of 2.at n=30A053159
• Nonprimes n such that n+cototient(n) is a power of 2.at n=24A053162
• Numbers of the form 2^i*5^j where i+j is even.at n=39A054901
• a(n) = (9*2^n + (-2)^n)/4 for n>0.at n=15A056486
• a(n) is the smallest number such that a(n)+1 is a prime and the largest power of 2 which divides it is 2^n.at n=15A057777
• Numbers k such that sigma(phi(k)) is a prime.at n=41A062514
• Numbers k such that k = 2*phi(k) + phi(phi(k)).at n=28A063920
• a(n) = gcd(Phi(n!), Phi(n^n), Phi(lcm(1..n))).at n=21A064449
• a(n) = gcd(Phi(n!), Phi(n^n), Phi(lcm(1..n))).at n=19A064449