65528

Appears in sequences

• a(1) = 2, a(n) = sigma(a(n-1)).at n=14A007497
• Numerator of [x^(4n+2)] in the Taylor series -log(cot(x)*tanh(x)).at n=3A012870
• a(n) = 4^n - n.at n=8A024037
• Numbers n such that uphi(sigma(n)) = n, where the uphi is the unitary phi function A047994.at n=24A030164
• Composite numbers k such that phi(k + d(k)) = phi(k) + d(k), where phi() = A000010(), d() = A000005().at n=27A063702
• 2^(n-1) - (prime(n) mod n).at n=16A077686
• a(n) = 3*a(n-1) - a(n-2) - 3*a(n-3) + 2*a(n-4).at n=16A084174
• Divisors of perfect numbers (A000396), sorted.at n=36A096360
• a(n) = sigma() [A000203] applied n times to prime(n).at n=8A101303
• Number of bits required to represent binomial(2^n, 2^(n-1)).at n=16A112884
• Divisors of 33550336, the 5th perfect number.at n=16A133025
• Triangle read by rows: row n lists divisors of n-th perfect number A000396(n).at n=50A133031
• Divisors of 16775168 (half the 5th perfect number).at n=15A138815
• Triangle read by rows: row n lists the proper divisors of n-th perfect number A000396(n).at n=46A139246
• Triangle read by rows: row n lists the divisors of n-th perfect number A000396(n) that are multiples of n-th Mersenne prime A000668(n).at n=20A139247
• a(n) = 64*n^2 - 8.at n=31A158487
• a(n) = 8*(2^n - 1).at n=12A159741
• Monotonic ordering of nonnegative differences 4^i-8^j, for 40>= i>=0, j>=0.at n=26A192167
• Fibonacci 14-step numbers, a(n) = a(n-1) + a(n-2) + ... + a(n-14).at n=17A220469
• Non-unitary amicable numbers.at n=21A259037