18130

Appears in sequences

• phi(n) is equal to the sum of prime factors and exponents of n-1.at n=5A039773
• Number of partitions satisfying cn(1,5) + cn(4,5) <= cn(0,5) + cn(2,5) and cn(1,5) + cn(4,5) <= cn(0,5) + cn(3,5).at n=44A039864
• Triangle read by rows: T(n,k) = (n+1,k)-th element of (M^6-M)/5, where M is the infinite lower Pascal's triangle matrix, 1<=k<=n.at n=32A096040
• Number of compositions of n in which the smallest part is equal to the number of parts.at n=47A098133
• a(n) is the smallest number, larger than the previous, such that the RMS (Root Mean Square) of a(0) through a(n) is an integer.at n=12A141393
• Shifts left when Dirichlet convolution with a (DC:(b,a)->c) applied 6 times.at n=6A144820
• Number of binary strings of length n with no substrings equal to 0001 0111 or 1100.at n=17A164484
• Sophie Germain 5-almost primes.at n=35A211162
• Numbers k such that A090086(k), the smallest pseudoprime to base k (not necessarily exceeding k), is a Carmichael number.at n=25A293203
• Numbers k such that A360119(k) > 1, but which have no divisors d > 1 such that d+1 is also a divisor.at n=45A360129
• Triangle read by rows: T(n, k) = [x^k] (n*x + 1)*Hypergeometric([-n, -n + 1], [1], x).at n=40A371401