18108

Appears in sequences

• a(n) = n!*(1 + Sum_{i=1..n} 1/i).at n=7A000774
• Number of homogeneous primitive partition identities of degree 6 with largest part n.at n=16A007344
• a(n) is the concatenation of n and 6n.at n=17A009440
• Maximal elements of pairs of "Super Unitary Amicable Numbers", sorted by their minimal elements.at n=38A045614
• a(n) = n! * Sum_{k|n} (Sum_{j=1..k} 1/j); the k-sum is over the positive divisors, k, of n.at n=6A067710
• Multiples of 3018.at n=5A086746
• Indices of primes in sequence defined by A(0) = 97, A(n) = 10*A(n-1) - 63 for n > 0.at n=23A100998
• Triangle of coefficients of certain polynomials used with prime numbers as variables in the computation of the array A103728.at n=28A103718
• Number of permutations of n objects such that no two-element subset is preserved.at n=8A137482
• Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, -1), (-1, 0), (0, -1), (1, 1)}.at n=11A151384
• Number of permutations of 1..n containing the relative rank sequence { 231645 } at any spacing.at n=3A159144
• G.f. is the polynomial (1-x^3) * (1-x^6) * (1-x^9) * (1-x^12) * (1-x^15) * (1-x^18) * (1-x^21) * (1-x^24) * (1-x^27) * (1-x^30) * (1-x^33) * (1-x^36) * (1-x^39) / (1-x)^13.at n=6A162631
• G.f. satisfies A(x)/A(x^2) = (1 + 9x + 9x^2 + 9x^3 + ...).at n=16A176201
• a(n) = n*(14*n - 1).at n=36A195024
• a(n) is a refactorable number and the sum of all refactorable numbers <= a(n) is also a refactorable number.at n=35A235177
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 534", based on the 5-celled von Neumann neighborhood.at n=39A272788
• Number of partitions of n-th triangular number (A000217) into distinct triangular parts.at n=41A288126
• Number of nX6 0..1 arrays with every element equal to 0, 1, 2 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero.at n=2A302067
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 2 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero.at n=30A302069
• Number of 3Xn 0..1 arrays with every element equal to 0, 1, 2 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero.at n=5A302070