68688

Appears in sequences

• Numbers with 50 divisors.at n=15A175756
• Sequence defined by the recurrence formula a(n+1)=sum(a(p)*a(n-p)+k,p=0..n)+l for n>=1, with here a(0)=1, a(1)=1, k=-1 and l=0.at n=14A176855
• Number of 6-element subsets of {1, 2, ..., n} having pairwise coprime elements.at n=30A186982
• Numbers with prime factorization pq^4r^4.at n=14A190012
• Number of (w,x,y,z) with all terms in {1,...,n} and |x-y|=|y-z|.at n=36A212679
• Number of length n+3 0..5 arrays with some disjoint pairs in every consecutive four terms having the same sum.at n=8A247530
• Number of magic and semi-magic squares of order n composed of the numbers from 1 to n^2, counted up to rotations and reflections.at n=3A271103
• Numbers with digits 6 and 8 only.at n=41A284635
• a(n) is the determinant of the 2 X 2 matrix whose entries (when read by rows) are the n-th primes ending in 1, 3, 7, 9 respectively.at n=25A335592
• Numbers that have exactly two exponents in their prime factorization that are equal to 4.at n=21A386805