21616

Appears in sequences

• Expansion of g.f. 1/((1-4*x)*(1-6*x)*(1-8*x)).at n=4A019333
• Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 42.at n=6A031720
• a(n)*a(n+3) - a(n+1)*a(n+2) = 2^n, given a(0)=1, a(1)=1, a(2)=6.at n=11A080879
• a(n)*a(n+3) - a(n+1)*a(n+2) = 2^n, given a(0)=1, a(1)=3, a(2)=7.at n=10A080882
• Largest achievable determinant of a 3 X 3 matrix whose elements are 9 distinct nonnegative integers chosen from the range 0..n.at n=17A097401
• Numbers k such that the number of prime divisors of the k-th Catalan number (counted with multiplicity) divides k.at n=37A121612
• a(n) = the number of permutations (p(1), p(2), ..., p(n)) of (1,2,...,n) where, for each k (2 <= k <= n), the sign of (p(k) - p(k-1)) equals the sign of (p(n+2-k) - p(n+1-k)).at n=9A137782
• a(n) = 49*n^2 + 7.at n=20A158481
• Irregular triangle read by rows: T(n,k) is the number of degree-n permutations without overlaps which furnish k new permutations without overlaps upon the addition of an (n+1)st element, 2 <= k <= 1 + floor(n/2).at n=44A259689
• Intersection of A003052 and A283002.at n=34A283003
• Number of partitions of n with ten parts in which no part occurs more than twice.at n=35A320598
• Number of different multisets that can be obtained by choosing a prime index (or a prime factor) of each integer from 2 to n.at n=44A355746
• G.f. A(x) satisfies A(x) = Sum_{n>=0} x^n * (1+x)^(n*(3*n+1)/2) / A(x)^(n*(n+1)/2).at n=10A380679
• Numbers k whose binary expansion contains 2 adjacent 1's and A391571(k) = k.at n=47A391581