31985

Appears in sequences

• a(n) = Sum_{k = 1..10^n} number of primes (counted with multiplicity) dividing k (A001222).at n=4A071811
• Number of subsets of {1, ..., n} that are double-free or sum-free.at n=18A088813
• Number of runs of 0's of odd length in all ternary words of length n.at n=9A119916
• Number of n X n 0..1 arrays with each 1 horizontally or vertically adjacent to 0, 1, 2 or 4 1's.at n=3A295710
• Number of nX4 0..1 arrays with each 1 horizontally or vertically adjacent to 0, 1, 2 or 4 1s.at n=3A295712
• T(n,k)=Number of nXk 0..1 arrays with each 1 horizontally or vertically adjacent to 0, 1, 2 or 4 1s.at n=24A295716
• Number of prime numbers of the form k^2 + k + 41 below 10^n.at n=9A319906
• Number of primes of the form P(k) = k^2 + k + 41 for k <= 10^n, where P(k) is Euler's prime-generating polynomial A202018.at n=5A331876