42900

Appears in sequences

• a(n) = number of (s(0), s(1), ..., s(n)) such that s(i) is a nonnegative integer and |s(i) - s(i-1)| <= 1 for i = 1,2,...,n, s(0) = 2, s(n) = 5. Also a(n) = T(n,n-3), where T is the array in A026323.at n=9A026328
• Fifth column (m=4) of triangle A060098.at n=14A060100
• Fifth column (m=4) of triangle A060102.at n=7A060104
• Product of all primes contained as binary substrings in binary representation of n.at n=45A078828
• Positive integers i for which A112049(i) == 9.at n=11A112069
• a(n) = binomial(2*n,n)*(n+3)^2/(n+1).at n=7A119575
• Numbers with prime factorization pqrs^2t^2.at n=20A189989
• Magic sums of 4 X 4 magic squares composed of odd squares.at n=18A271582
• Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 449", based on the 5-celled von Neumann neighborhood.at n=7A272253
• Smallest integer such that the sum of its n smallest divisors is a square.at n=43A289712
• a(n) = Product_{d|n, d<n} A019565(A003714(d)), where A003714(n) is the n-th Fibbinary number.at n=31A300834
• Numbers that are product of a hexagonal number (A000384) and a square pyramidal numbers (A000330) in at least two ways.at n=17A306121
• Exponential (2,3)-perfect numbers: numbers m such that esigma(esigma(m)) = 3m, where esigma(m) is the sum of exponential divisors of m (A051377).at n=38A328132
• Number of polygonal cacti on n unlabeled nodes with every polygon having an even number of edges.at n=27A332651
• Numbers m such that the largest digit in the decimal expansion of 1/m is 3.at n=33A350814
• Triangle read by rows: T(n, k) is the number of walks of length 2*n on the N X N grid with unit steps in all four directions (NSWE) starting at (0, 0). k is the common value of the x- and the y-coordinate of the endpoint of the walk.at n=25A380119