18340

Appears in sequences

• Number of triangles a queen can make (starting anywhere) on an n X n board.at n=21A030117
• Number of nonempty subsets of {1,2,...,n} in which exactly 2/5 of the elements are <= (n-1)/2.at n=17A047177
• Number of nonempty subsets of {1,2,...,n} in which exactly 2/5 of the elements are <= (n-2)/2.at n=17A047188
• McKay-Thompson series of class 33B for Monster.at n=41A058637
• Numbers k such that cototient(k) is a square and sets a new record for squares.at n=30A063753
• Where A007535 reaches a record.at n=37A098653
• Numbers n such that n^3 can be represented as sum of (at least two) consecutive squares.at n=8A163390
• a(n) = Sum_{k=1..n} k*lcm(k,k')/gcd(k,k'), where k' is arithmetic derivative of k.at n=22A190122
• Number of arrays of n+2 integers in -2..2 with sum zero and adjacent elements differing in absolute value.at n=7A202956
• T(n,k)=Number of arrays of n+2 integers in -k..k with sum zero and adjacent elements differing in absolute value.at n=43A202962
• Integers m such that m^3 is the sum of two or more consecutive integer squares.at n=19A212018
• a(n) = n*(n+1)*(13*n+2)/6.at n=20A257093
• Numbers k such that A090086(k), the smallest pseudoprime to base k (not necessarily exceeding k), is a Carmichael number.at n=26A293203
• Number of n X 5 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 2 neighboring 1s.at n=11A297296
• Expansion of Sum_{k>=0} x^(k*(k+1)/2) * Product_{j=1..k} (1 + x^j)^j.at n=46A306733