20128

Appears in sequences

• Number of n-bead bracelets (turnover necklaces) of two colors with 6 red beads and n-6 black beads.at n=28A005513
• Numbers k such that phi(sigma(k)+k) = sigma(k-phi(k)), where phi is A000010 and sigma is A000203.at n=33A063710
• Sum of squares of digits of n is equal to the largest prime factor of n reversed, where the largest prime factor is not a palindrome.at n=30A074303
• Shifts 4 places left under Dirichlet convolution.at n=51A144368
• Partial sums of A027444.at n=16A152457
• Number of permutations of 1..n with all differences of elements separated by distances 1 through 7 being respectively unique.at n=18A170813
• Fibonacci + Goldbach: a(1)=6, a(2)=8 and for n>=3, a(n)=g(a(n-1)) + g(a(n-2)), where for m>=3, g(2*m) is the maximal prime p < 2*m such that 2*m - p is prime.at n=22A216275
• Number of (n+1)X(2+1) 0..3 arrays with the maximum minus the lower median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one.at n=1A238307
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with the maximum minus the lower median of every 2X2 subblock differing from its horizontal and vertical neighbors by exactly one.at n=4A238311
• Number of n-node unlabeled rooted trees with thinning limbs and root outdegree (branching factor) 8.at n=13A244709
• Number of length n+4 0..7 arrays with every five consecutive terms having two times the sum of some three elements equal to three times the sum of the remaining two.at n=3A248986
• T(n,k)=Number of length n+4 0..k arrays with every five consecutive terms having two times the sum of some three elements equal to three times the sum of the remaining two.at n=48A248987
• Number of length 4+4 0..n arrays with every five consecutive terms having two times the sum of some three elements equal to three times the sum of the remaining two.at n=6A248991
• Numbers which are representable as a sum of seventeen but no fewer consecutive nonnegative integers.at n=28A270302
• a(n) is the smallest number which has a water-capacity of n.at n=14A275339
• Length of longest cycle in n-th row of A329278 (triangular numbers mod 2^n).at n=16A330766
• Number of strict chains of divisors from n! to 1.at n=7A337105
• Even composite positive integers m such that A052918(m-1)^2 == 1 (mod m).at n=14A338313
• Number of binary strings of length n that contain the substring 1000.at n=15A373046
• Infinite square array, where row r >= 0 is the orbit of r under the map A380873: concatenate(sum of digits, product of digits).at n=85A380872