47859

Appears in sequences

• Numbers n such that (i) the sum of the distinct primes dividing n is divisible by the largest prime dividing n and (ii) n has exactly 4 distinct prime factors and (iii) n is squarefree.at n=18A071143
• Group the triangular numbers so that the n-th group sum is a multiple of n. 1, (3, 6, 10, 15), (21), (28), (36, 45, 55, 66, 78), (91, 105, 120, 136, 153, 171, 190), ... Sequence contains n-th group sum divided by n.at n=37A114032
• Numbers n such that the sum of the distinct prime divisors of n that are congruent to 1 mod 4 equals the sum of the distinct prime divisors congruent to 3 mod 4.at n=27A215949
• Triangle read by rows: T(n,k) is the number of permutations of n elements with k the (smallest) header (first element) of the longest descending subsequence.at n=41A224652
• Expansion of Product_{k>=1} ((1 - x^(3*k))/(1 - x^k))^k.at n=20A263346
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 721", based on the 5-celled von Neumann neighborhood.at n=32A273447
• Numbers k such that k![6] + 2 is prime, where k![6] = A085158(k) = sextuple factorial.at n=27A287207
• a(n) = n*(2*n - 3 - (-1)^n)*(5*n - 2 + (-1)^n)/16.at n=42A308025
• Numbers m such that m^2 + p^2 = k^2, with p > 0, where p = A007954(m) = the product of digits of m.at n=12A334558
• Numbers k such that omega(k) = 4 and the largest prime factor of k equals the sum of its remaining distinct prime factors, where omega(k) = A001221(k).at n=28A383728