66380

Appears in sequences

• a(n) is the least k such that (k*prime(n)#)^2 + 1, ((k+1)*prime(n)#)^2 + 1 and ((k+2)*prime(n)#)^2 + 1 are 3 primes, where prime(n)# is the n-th primorial.at n=44A098765
• Numbers k such that k and k^2 use only the digits 0, 3, 4, 6 and 8.at n=15A136931
• T(n,k)=Number of nXk arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, without move-in move-out straight through or left turns.at n=37A221817
• Number of 2 X n arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, without move-in move-out straight through or left turns.at n=7A221818
• a(n) is the number of ways to split [n] = {1,2,...,n} into two (possibly empty) complementary intervals {1,2,...,i} and {i+1,i+2,...,n} and then, if both intervals are nonempty, select 2 nonempty blocks/cells (i.e., subintervals) from each of them, or if one of the intervals is empty, select 2 nonempty blocks/cells from the nonempty interval.at n=24A353232