1013512

Appears in sequences

• Number of anti-divisors of n (A066272) sets a record.at n=41A073638
• Lesser of a pair of records in A066272.at n=5A093071
• a(n) = ((2*n-1)!! + (-1)^((n-1)*(n-2)/2))/2.at n=7A220092
• (A001147(n+1)-1)/2, equals the index of A249348(n) within the triangular numbers A000217.at n=7A249349
• Triangle T(n,k) read by rows with T(n,0) = (2*n)! / (2^n * n!) for n >= 0 and T(n,k) = (Sum_{i=k..n} binomial(i-1,k-1) * 2^i * i! / (2*i)!) * (2*n)! / (2^n * n!) for 0 < k <= n.at n=38A350557