253890

Appears in sequences

• Numbers k such that sopfr(k) = ud(k), where sopfr = A001414 and ud = A034444.at n=3A064029
• Numbers k such that (1/k) * Sum_{d|k} d*sigma(d) is an integer.at n=29A069520
• Numbers k such that 2*k+1, 4*k+1, 8*k+1, 16*k+1 and 32*k+1 are primes.at n=30A124413
• Denominator of Sum_{k=1..n} 1/A045542(k).at n=10A214391
• Number of permutations of n (distinct) elements from [2n] without consecutive adjacent values.at n=6A375022
• Highest integer k such that the multiplicative group modulo k is a subgroup of the symmetric group S_n.at n=30A380222