67431

Appears in sequences

• Numbers n such that |phi(n+1)-phi(n)| = |d(n+1)-d(n)|, where phi is Euler's totient function and d(n) = number of divisors of n.at n=11A066219
• Numbers n such that 9*10^n + 8*R_n - 1 is prime, where R_n = 11...1 is the repunit (A002275) of length n.at n=19A103109
• a(n) = (n+1)*(n+2)^2*(n+3)*(n+4)*(3*n+5)/240.at n=11A114243
• Triangle T, read by rows, that satisfies matrix equation: T - (T-I)^2 = C, where C is Pascal's triangle.at n=30A117269
• Odd n such that 2*phi(n) < n, but there does not exist an even k < n with phi(k) = phi(n).at n=11A118700
• Multiples of 1729, the Hardy-Ramanujan number.at n=39A138129
• Numbers n such that (n^6 + 1091)/4 is prime.at n=33A181112
• Number of binary arrays indicating the locations of trailing edge maxima of a random length-n 0..3 array extended with zeros and convolved with 1,4,6,4,1.at n=24A221994
• Numbers n such that phi(n) + d(n) = phi(n+1) + d(n+1), where phi(n) is the Euler totient function of n and d(n) the number of divisors of n.at n=8A259496
• Sum of all the parts in the partitions of n into 6 parts.at n=39A308867
• a(n) = Product_{d|n, d>1} prime(1+(d mod 8)).at n=44A320108
• Numbers k such that sigma(k) = psi(k) + tau(k)^2 + omega(k)^3.at n=21A392520