20268

Appears in sequences

• Numbers n such that [A070080(n), A070081(n), A070082(n)] is an obtuse isosceles integer triangle with prime side lengths.at n=27A070135
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, -1, 1), (-1, 1, 1), (0, 1, 1), (1, 0, -1)}.at n=10A148371
• Sixth derivative of f_n at x=1, where f_n is the n-th of all functions that are representable as x^x^...^x with m>=1 x's and parentheses inserted in all possible ways.at n=25A215836
• Triangle T(n,k) in which n-th row lists the values of the n-th derivative at x=1 of all functions that are representable as x^x^...^x with n x's and parentheses inserted in all possible ways; n>=1, 1<=k<=A000081(n).at n=25A216349
• Triangle T(n,k) in which n-th row lists in increasing order the values of the n-th derivative at x=1 of all functions that are representable as x^x^...^x with n x's and parentheses inserted in all possible ways; n>=1, 1<=k<=A000081(n).at n=27A216350
• Number of terms of A072873 less than or equal to 10^n.at n=40A267757
• a(n) = Sum_{k=0..n} k^3 * binomial(n-k, k).at n=13A277361
• The forgotten topological index of the Aztec diamond AZ(n) (see the Ramanes et al. reference, Theorem 2.1).at n=11A292346
• Product_{k>=1} 1/(1 - a(k)*x^k) = 1 + Sum_{k>=1} k^2*x^k.at n=19A316086
• Number of Lyndon compositions (aperiodic necklaces of positive integers) with sum n and successive parts (including the last with the first part) being indivisible.at n=34A318746
• a(n) is the n-th nonnegative number to light exactly n segments when displayed on a calculator.at n=24A339700