27951

Appears in sequences

• Number of non-stereoisomeric paraffins with n carbon atoms.at n=22A000627
• Partially directed animals on the square lattice.at n=10A033565
• Number of labeled 2-trees with n nodes.at n=6A036361
• a(0)=1, a(1)=1, a(n) = 11*a(n/2) for even n, and a(n) = 10*a((n-1)/2) + a((n+1)/2) for odd n >= 3.at n=24A116525
• Triangle read by rows: T(n,r) = number of maximum r-uniform acyclic hypergraphs of order n and size n-r+1, 1 <= r <= n+1.at n=30A135021
• a(n+1)-+a(n)=prime, a(n+1)*a(n)=Average of twin prime pairs, a(1)=1,a(2)=4.at n=36A154493
• Totally multiplicative sequence with a(p) = a(p-1) + 10 for prime p.at n=23A166707
• a(n) = n*(n+1)*(6*n-5)/2.at n=21A172082
• Partial sums of A007694.at n=44A174030
• Number of 0..n arrays x(0..3) of 4 elements with each no smaller than the sum of its previous elements modulo (n+1).at n=19A200253
• Alternating sum of the fourth powers of the first n odd-indexed Fibonacci numbers.at n=4A203172
• Number of (w,x,y,z) with all terms in {1,...,n} and w<2x and y>=3z.at n=22A212511
• Number of (w,x,y,z) with all terms in {0,...,n} and w, x, and y even.at n=20A212759
• a(n) = the least k for which A255326(k) = n; positions of records in A255326.at n=13A255409
• Numbers with a minimum of 6 polygonal roots, excluding itself.at n=31A275256
• Heinz numbers of integer partitions such that the difference between the length of the minimal square containing and the maximal square contained in the Young diagram is 1.at n=41A325179
• Triangle read by rows: T(n,k) is the number of proper vertex colorings of the n-complete tripartite graph using exactly k interchangeable colors, 3 <= k <= 3*n.at n=66A385432
• Odd numbers k such that A173557(k) = A173557(sigma(k)), where A173557(n) is multiplicative with a(p^e) = p-1 and sigma is the sum of divisors function.at n=27A387159