47047

Appears in sequences

• a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (odd natural numbers), t = (primes).at n=40A024603
• a(n) = Sum_{i=1..floor((n+1)/4)} a(2*i-1) * a(n-2*i+1), with a(1)=a(2)=1 and a(3)=7.at n=14A024733
• a(n) = (n+1)*(n+2)*(n+3)*(n+4)*(5*n^2 + 19*n + 15)/360.at n=10A107963
• Numbers n for which phi(n)=sigma(n'), where phi is the Euler totient function, sigma is the sum of divisors and n' the arithmetic derivative of n.at n=12A189057
• Number of length n+2 0..3 arrays with at most one downstep in every n consecutive neighbor pairs.at n=9A258732
• Number of ordered set partitions of [n] with nondecreasing block sizes and maximal block size equal to ten.at n=4A272500
• Terms of A349937 that are not divisible by 3: numbers k > 1 not divisible by 2 or 3 such that A309906(k-1) < A309906(k) > A309906(k+1).at n=36A349941