18491

Appears in sequences

• Number of partitions of n with equal nonzero number of parts congruent to each of 1 and 2 (mod 5).at n=51A035566
• Composite numbers whose prime factors contain no digits other than 1 and 4.at n=6A036304
• a(n) = Sum_{d|n} p(d), where p(d) = A000041 = number of partitions of d.at n=35A047968
• Number of parts that are visible in one of the three views of the section model of partitions version "tree" with n sections.at n=33A194805
• Number of nonnegative integer arrays of length 2n+5 with new values 0 upwards introduced in order, no three adjacent elements all unequal, and containing the value n+1.at n=17A211850
• Largest number in a 6-tuple (a,b,c,d,e,f) of positive integers satisfying the Markoff(6) equation a^2 + b^2 + c^2 + d^2 + e^2 + f^2 = 3*a*b*c*d*e*f.at n=36A227204
• Number of nX3 0..1 arrays with every element equal to 0, 2, 3, 4 or 6 king-move adjacent elements, with upper left element zero.at n=7A298323
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 2, 3, 4 or 6 king-move adjacent elements, with upper left element zero.at n=47A298328
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 2, 3, 4 or 6 king-move adjacent elements, with upper left element zero.at n=52A298328
• Numbers p^2*q, p > q odd primes such that q does not divide p-1, and q does not divide p+1.at n=34A350421
• Number of odd-length integer partitions of n whose parts do not have the same mean as median.at n=40A359896
• Composite numbers that contain only nonprime digits and whose prime factors contain only nonprime digits.at n=36A383934
• Numbers k such that sigma(k) = psi(k) + 2 * tau(k).at n=30A387962