70720

Appears in sequences

• Partial sums of A051923.at n=11A050494
• Factorial splitting: write n! = x*y*z with x<y<z and x maximal and z is minimal; sequence gives value of y.at n=14A061031
• Expansion of (1 + x^2*C)*C^2, where C = (1 - sqrt(1-4*x))/(2*x) is g.f. for Catalan numbers, A000108.at n=10A071717
• Number of 3 X n semireduced Latin rectangles, that is, having exactly n fixed points in the first two rows.at n=3A176901
• Number of solutions to a+b+c < d+e with each of a,b,c,d,e in {1..n+1}.at n=11A179441
• Triangle read by rows: the x = 1+q Narayana triangle at m=2.at n=43A243660
• a(n) = A351477(n) * FA where F is the Fermat point of a primitive integer-sided triangle ABC with A < B < C < 2*Pi/3 and FA + FB + FC = A336329(n).at n=5A351801
• Number of coalescent histories for matching gene trees and species trees with n leaves and a 5-leaf seed tree.at n=7A355044
• Factorial splitting: write n! = x*y*z with x <= y <= z and minimal z-x; sequence gives value of y.at n=17A355190
• Least number k such that there are exactly n ways to choose a different binary index of each binary index of k.at n=13A367910
• Sorted positions of first appearances in A367905.at n=13A367911
• Triangle T(n,k) (1 <= k <= n) read by rows: T(n,k) = c_n * F(k)/F(k+2) where c_n = LCM of F(3), F(4), ... F(n+2) (and F() are the Fibonacci numbers).at n=26A374667
• The Geode Bi-Tri infinite rectangular array, read by upward antidiagonals.at n=37A383453
• a(n) = 2*binomial(2*n+4,n)*(n+3)/(n+2).at n=7A383456