27645
domain: N
Appears in sequences
- a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2) and t = A008578 ({1} U primes).at n=42A023862
- Integers m such that phi(m) is equal to the sum of (the product of prime factors) and (the product of exponents) of m-1.at n=6A039777
- Average of terms in n-th row of A077529.at n=23A077532
- Numbers whose sum of triangular divisors is also a divisor and greater than 1.at n=38A209311
- Number of (w,x,y,z) with all terms in {1,...,n} and w<x>=y<=z.at n=19A212415
- Squarefree nonprimes n with a divisor d such that phi(n) divides n+d.at n=26A217741
- -3-Knödel numbers.at n=31A225507
- Number of numbers in row n of the array at A243848.at n=24A243850
- Numbers n such that phi(n) = phi(n+11), with Euler's totient function phi = A000010.at n=25A276504
- Denominator of (1/3)*n*(n + 2)/((1 + 2*n)*(3 + 2*n)).at n=47A300295
- Number of length n word structures with all distinct run-lengths using at most 3 symbols.at n=22A351639
- a(n) = n*2^10 - 3.at n=26A362361
- Numbers k such that phi(k) divides k + 3.at n=9A392283