45996

Appears in sequences

• Numbers k such that sigma(phi(k)) = phi(sigma(k)).at n=15A033632
• Numbers k such that phi(2*sigma(k)) = 2*sigma(phi(k)).at n=19A067709
• Numbers k such that sigma(phi(k)) divides phi(sigma(k)).at n=27A073858
• Numbers k such that sigma(phi(k)) == phi(sigma(k)) (mod k), that is, A033632(k)/k is an integer.at n=17A092584
• Number of (n+1)X(2+1) 0..2 arrays with the maximum plus the upper median plus the lower median minus the minimum of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one.at n=3A237326
• Number of (n+1)X(4+1) 0..2 arrays with the maximum plus the upper median plus the lower median minus the minimum of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one.at n=1A237328
• T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the maximum plus the upper median plus the lower median minus the minimum of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one.at n=11A237332
• T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the maximum plus the upper median plus the lower median minus the minimum of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one.at n=13A237332
• a(1) = 1; a(n+1) = Sum_{d|n} sigma(n/d)*a(d), where sigma = sum of divisors (A000203).at n=43A307817
• a(n) is the smallest index k such that Sum_{m=1..k} 1/z(m) > n where z(m) is the imaginary part of the m-th nontrivial zero of the Riemann zeta function, n=0,1,2,...at n=6A332614
• Number of integer partitions of n whose median part is the smallest.at n=48A361860