117117

Appears in sequences

• a(n) = number of (s(0), s(1), ..., s(n)) such that every s(i) is a nonnegative integer, s(0) = 0, s(1) = 1, s(n) = 4, |s(i) - s(i-1)| <= 1 for i >= 2. Also a(n) = T(n,n-4), where T is the array defined in A026105.at n=10A026110
• a(n) = n*(n^3 - 1)/2.at n=20A027482
• a(n) = 3*(n+1)*binomial(n+2,6).at n=8A027779
• a(n) = 9*(n+1)*binomial(n+2,9)/2.at n=5A027782
• Lucky numbers that are concatenations of a number k with itself.at n=14A032650
• T(n,n-6), where T is the array in A055830.at n=20A055833
• Numbers of the form k*(k^3 +- 1)/2.at n=42A057590
• Triangle read by rows: T(n,k) (n >= 2, k >= 0) is the number of non-crossing connected graphs on n nodes on a circle, having k interior faces. Rows are indexed 2,3,4,...; columns are indexed 0,1,2,....at n=42A089434
• 3n concatenated with itself.at n=38A248038
• Number of non-equivalent ways to place 2 non-attacking kings on an n X n board.at n=36A279111
• Number of 2 X 2 matrices having all elements in {-n,..,0,..,n} with determinant = permanent.at n=19A280059
• Number of n X 2 0..1 arrays with each 1 adjacent to 3, 4 or 5 king-move neighboring 1s.at n=14A296984
• a(n) = ((p-1)^3 - (p-1)^2)/4 where p is the n-th prime.at n=21A331764
• Numbers that are divisible by the squares of two distinct primes and whose arithmetic derivative (A003415) is a squarefree number of the form 4k+2.at n=41A368697