45220

Appears in sequences

• Number of distinct perforation patterns for deriving (v,b) = (n+2,n) punctured convolutional codes from (2,1).at n=9A007223
• a(n) = Sum_{k=0..floor((n-1)/2)} T(n,k) * T(n,k+1), with T given by A008315.at n=9A027302
• Expansion of (Product_{j>=1} (1-(-x)^j) - 1)^20 in powers of x.at n=8A047645
• Denominators of column 2 of table described in A051714/A051715.at n=16A051719
• Numbers k such that phi(k) = bigomega(k)*tau(k)^2.at n=38A068540
• Numbers k such that k and k^2 use only the digits 0, 2, 4, 5 and 8.at n=55A136900
• Square spiral of sums of selected preceding terms, starting at 1.at n=47A141481
• Given n and a constant C, define a sequence b(m) by the recurrence in the comments; a(n) = smallest positive integer C such that for some prime p the denominators of all b(m) are powers of p (conjectured).at n=11A216814
• Number x such that sigma(x) = usigma(x) + (-1)sigma(x), where sigma(x) is the sum of divisors of x (A000203), usigma(x) is the sum of unitary divisors of x (A034448) and (-1)sigma(x) is defined in A049060.at n=5A258106
• a(n) = 2*n*(16*n - 13).at n=38A263228
• Expansion of (A(x)^2 - A(x^2))/2 where A(x) = A000108(x) - 1.at n=11A275206
• Triangle read by rows: T(n,k) = number of ways to insert n pairs of parentheses in k words.at n=56A275431
• Numbers m having greatest prime power divisor d such that d is smaller than the difference between m and the largest prime smaller than m and d is smaller than the difference between m and twice the largest prime smaller than m/2.at n=16A290290
• Wiener index of the n X n queen graph.at n=14A292057
• a(n) = (1/24)*n*((4*n + 3)*(2*n^2 + 1) - 3*(-1)^n).at n=19A325656