51120

Appears in sequences

• a(n) = Sum_{k=0..2} (n+k)! * C(2,k).at n=7A001344
• Number of strongly asymmetric sequences of length n.at n=11A002842
• Binomial triangle based on factorials.at n=38A076571
• Numbers k such that 2^k - 1 is divisible by (k-1).at n=33A087965
• Structured triakis icosahedral numbers (vertex structure 4).at n=17A100172
• Coefficients of tribonacci numbers expansion : similar to the Fibonacci number expansion given in Steve Roman's Umbral Calculus.at n=29A137431
• Square array A(row,col) = Sum_{k=0..row} binomial(row,k)*(1+col+k)!, read by descending antidiagonals as A(0,0), A(0,1), A(1,0), A(0,2), A(1,1), A(2,0), ...at n=30A276588
• Transpose of A276588.at n=33A276589
• Triangle read by rows: T(n,k) is the number of linear chord diagrams on 2n vertices with one marked chord such that exactly k of the remaining n-1 chords contain the marked chord.at n=34A336600
• T(n, k) = [x^n] 2^n*P(n, x), where P(n, x) = (1 + 4*x)^(n + 1) + (1 - 2^(-2*n-1))*(2 + 4*x)^(n + 1). Triangle read by rows, T(n, k) for 0 <= k <= n+1 if n >= 0 and by convention T(-1, 0) = 0.at n=18A342317