262140

Appears in sequences

• a(n) = 2*a(n-1) if n odd else 2*a(n-1) + 6.at n=16A014131
• a(n) = 2^n - 4.at n=16A028399
• Number of primitive (aperiodic) palindromes using a maximum of four different symbols.at n=16A056460
• Number of primitive (period n) periodic palindromes using a maximum of four different symbols.at n=16A056495
• Largest solution of phi(x) = 2^n.at n=16A058215
• a(n) = 4^n - 4.at n=9A058896
• Numbers k such that usigma(phi(k)) is a prime.at n=40A065875
• Numbers k such that phi(k) is a perfect 8th power.at n=29A078168
• Numbers n such that sigma(uphi(n)) = n where uphi is the unitary totient (or unitary phi) function (see A047994).at n=26A120116
• Numbers such that 2*UnitaryPhi(2*UnitaryPhi(n)) = n.at n=21A120453
• a(n) = 2 * A285917(n) for n >=2, a(0) = a(1) = 0.at n=17A120672
• a(n) = Sum_{k=0..n} floor(C(n,k)/2).at n=19A120739
• Row sums of triangle A166455.at n=17A166456
• Smallest number m such that exactly n editing steps (insert or substitute) are necessary to transform the binary representation of m into the least prime not less than m.at n=17A171402
• Second diagonal under the main diagonal in A172119 written in a square (see comment).at n=16A173033
• Monotonic ordering of nonnegative differences 8^i-4^j, for 40>= i>=0, j>=0.at n=32A192168
• a(n) = n^9 - n.at n=4A196289
• Numbers k such that phi(k) - 1 divides k, where phi is Euler's totient function.at n=6A202855
• Number of distinct infinite sets of primes congruent to a subset of 1..n mod n.at n=33A216850
• Number of idempotent 4X4 0..n matrices of rank 3.at n=30A224335