31138

Appears in sequences

• Number of nonempty subsets of {1,2,3,...,n} whose elements have an integer average.at n=17A051293
• Minimal peaks in digital expansions of Pi: positions of peaks equal to 1.at n=33A105275
• The number of primes between two consecutive Mersenne primes.at n=5A176559
• Numbers n such that sigma(n) divides sum_{k=1..n} tau(k), where tau(k) is the number of divisors of k (A000005) and sigma(n) is the sum of divisors of n (A000203).at n=6A182169
• Number of (n+2) X 3 binary arrays avoiding patterns 001 and 110 in rows, columns and nw-to-se diagonals.at n=31A202440
• Total sum of even parts in the last section of the set of partitions of n.at n=32A206436
• a(n) = Sum_{k=0..n} binomial(n,k) * binomial(4*n+3*k,k).at n=4A387432