43520

Appears in sequences

• Number of nonseparable toroidal tree-rooted maps with n + 2 edges and n + 1 vertices.at n=14A006414
• a(n) is least k such that k and 5k are anagrams in base n (written in base 10).at n=27A023097
• Numbers that are the sum of 4 nonzero squares in exactly 7 ways.at n=45A025363
• Numbers k that divide the (right) concatenation of all numbers <= k written in base 17 (most significant digit on left).at n=14A029462
• Numbers k such that k^3 has only even digits.at n=26A052004
• Number of walks of length n along the edges of an octahedron starting and ending at a vertex and also ( with a(0)=0 ) between two opposite vertices.at n=9A054881
• Triangle of partial row sums (prs) of triangle A055252.at n=56A055584
• Second column of triangle A055584.at n=9A055585
• Solutions to phi(gpf(x)) - gpf(phi(x)) = 14 = c are special multiples of 17, x = 17k, where greatest prime factors of factor k were observed from {2, 3, 5}, i.e., it is smaller than 17. See solutions to other even cases of c (=A070813): A007283 for 0, A070004 for 2, A070815 for 254, A070816 for 65534. Gpf = greatest prime factor.at n=39A070814
• Variance of time for a random walk starting at 0 to reach one of the boundaries at +n or -n for the first time.at n=16A072819
• Numbers k such that phi(k) is a perfect 7th power.at n=18A078167
• a(n) = Sum_{k=floor((n+1)/2)..n} J(k+1), J(k) = A001045(k).at n=15A129362
• The sum of the principal diagonals of an n X n spiral.at n=40A137930
• Sum of the principal diagonals of a 2n X 2n square spiral.at n=20A137931
• a(n) = binomial(n+2,3)*4^3.at n=14A141478
• Number of cycles of length 3 in the queen graph associated with an n X n chessboard.at n=17A144298
• Numerators of fractions in the approximation of the square root of 5 satisfying: a(n)= (a(n-1)+ c)/(a(n-1)+1); with c=5 and a(1)=0. Also product of the powers of two and five times the Fibonacci numbers.at n=9A163305
• Numbers n such that the products n*(sum of the reciprocals of the Collatz (3x+1) sequence beginning at n) are integers.at n=42A225878
• Records values in A072994.at n=60A251642
• a(n) = n*(n + 1)*(n + 2)*(9*n - 7)/12.at n=15A264852