338688

Appears in sequences

• Triangle read by rows, the Bell transform of n!*binomial(4,n) (without column 0).at n=30A049424
• Numbers n such that n=phi(phi(n)+sigma(n)) and n is not of the form 2*p where p is a Sophie Germain odd prime.at n=15A097652
• Triangle read by rows: T(n,k) is the number of Schroeder paths of length 2n and having k weak ascents (1<=k<=n). A Schroeder path of length 2n is a lattice path from (0,0) to (2n,0) consisting of U=(1,1), D=(1,-1) and H=(2,0) steps and never going below the x-axis. A weak ascent in a Schroeder path is a maximal sequence of consecutive U and H steps.at n=49A114655
• Trajectory of 2677889 under "x -> product of digits of x" map.at n=1A121108
• Trajectory of 26888999 under "x -> product of digits of x" map.at n=2A121109
• Trajectory of 3778888999 under "x -> product of digits of x" map.at n=3A121110
• Trajectory of 277777788888899 under "x -> product of digits of x" map.at n=4A121111
• Amicable triples. Sequence gives sigma values: A125490(n) + A125491(n) + A125492(n).at n=22A137231
• Number of permutations of 0..(n-1) with the sum of the maximum of each adjacent pair = n*(n-1)/2 + floor((n-1)^2/8).at n=8A180154
• Area A of the bicentric quadrilaterals such that A, the sides, the radius of the circumcircle and the radius of the incircle are integers.at n=14A219192
• Composite numbers m such that Product_{i=1..k} (p_i/(p_i-1)) / Sum_{i=1..k} (p_i/(p_i+1)) is an integer, where p_i are the k prime factors of m (with multiplicity).at n=19A230112
• Coefficients in expansion of Eisenstein series -q*(d/dq)(q*(d/dq)E_2).at n=21A282154
• Triangle read by rows. A generalization of unsigned Lah numbers, called L[2,1].at n=51A286724
• Triangle T(n,p) read by rows: the order of the semigroup of orientation-preserving partial transformations of n elements with height p.at n=51A289711
• Intersection of A001694 and A195069.at n=23A316499
• a(n) is the lowest nonnegative exponent k such that n!^k is the product of the divisors of n!.at n=26A344687
• Numbers of multiplicative persistence 7 which are themselves the product of digits of a number.at n=0A350186
• Square array A(i,j), i >= 0, j >= 0, read by antidiagonals: A(i,j) = Sum_{|X|=0..i} Sum_{|Y|=0..i} Product_{k=1..j} (1+X(k)+Y(k)), where X and Y are multi-indices of length j.at n=51A358628