18676

Appears in sequences

• Heptagonal (or 7-gonal) pyramidal numbers: a(n) = n*(n+1)*(5*n-2)/6.at n=28A002413
• a(n) = (1/24)*(n+1)*(n+3)*(n^2+22*n+88).at n=21A090950
• Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n having k long ascents and long descents. A long ascent (descent) in a Dyck path is a maximal sequence of at least 2 consecutive up (down) steps.at n=67A127155
• a(n) = a(n-1) + a(n-2) + n + 2 with n>1, a(0)=1, a(1)=2.at n=17A210728
• Least m>0 such that m^4 >= n!.at n=18A214448
• Even heptagonal pyramidal numbers.at n=20A218325