130048

Appears in sequences

• Numbers n such that usigma(cototient(n)) is a prime.at n=14A063719
• 2^(n-3)n(9n^2-9n+4).at n=8A086604
• Number of subsets of {1,..,n} containing at least one prime.at n=16A089820
• a(n) = 2*a(n-1) + 12*a(n-2).at n=8A091914
• Number of closed walks on C_5 tensor J_2.at n=10A101502
• Numbers with 22 divisors.at n=30A137485
• 10th column of A172119.at n=17A172319
• Number of binary words of length n which have no 0^b 1 1 0^a 1 0 1 0^b - matches, where a=1, b=2.at n=17A234591
• a(n) = 2*a(n-1) + 2*a(n-2) - 4*a(n-3), a(1) = 0, a(2) = 0, a(3) = 8.at n=15A297619
• Number of excursions of length n with Motzkin-steps avoiding the consecutive steps UU, HH, HD and DH.at n=29A329692
• Numbers of the form q*(2^k), where q is one of the Mersenne primes (A000668) and k >= 0.at n=58A335431
• Larger member of a noninfinitary amicable pair: numbers (k, m) such that nisigma(k) = m and nisigma(m) = k, where nisigma(k) is the sum of the noninfinitary divisors of k (A348271).at n=6A348344
• Triangle read by rows: T(n,k) (n >= 1, 1 <= k <= n) = number of subdigraphs of the transitive tournament on n nodes that have k weak components.at n=25A350609
• a(n) is the sum of the first 2*n nonzero n-bonacci numbers.at n=9A364145