39787

Appears in sequences

• Apocalypse primes: 10^665+a(n) has 666 decimal digits and is prime.at n=26A115983
• Numbers k that divide the sum of the first k nonprimes.at n=8A129749
• Unchanging value maps: number of nX4 binary arrays indicating the locations of corresponding elements unequal to no king-move neighbor in a random 0..1 nX4 array.at n=7A219399
• T(n,k)=Unchanging value maps: number of nXk binary arrays indicating the locations of corresponding elements unequal to no king-move neighbor in a random 0..1 nXk array.at n=58A219403
• Numbers n such that sigma(n+1) - sigma(n-1) = k*n for some integer k, where sigma(n) = A000203 (sum of divisors of n).at n=39A223137
• Numbers k such that sigma(k+1) divides sigma(k-1).at n=42A227304
• Solution to the problem of finding the number of comparisons needed for optimal merging of 3 elements with n elements.at n=43A239100
• Number of twice-partitions of n with no (1)'s.at n=17A358829
• Expansion of (1/x) * Series_Reversion( x * (1/(1-x^2) - x) ).at n=13A370839