109897

Properties

Appears in sequences

• Numerator of sum(1/(phi(k)sigma(k)),k=1..n), where phi(k) is the totient function and sigma(k) is the sum of the divisors function.at n=9A104526
• Primes p of the form p^2 + q - 1 where p < q are consecutive primes.at n=19A242231
• T(n,m) is the numerator of the resistance between two nodes located at the end of a side of length n of a rectangular electric network of n*m quadratic meshes in which all edges are replaced by one-ohm resistors, where T(n,m) is a square array read by descending antidiagonals.at n=40A357115
• Number of strict integer partitions of 2n not containing n.at n=42A365828
• Prime numbersat n=10446