93280
domain: N
Appears in sequences
- 4-dimensional analog of centered polygonal numbers: a(n) = n(n+1)*(n^2+n+4)/12.at n=32A006007
- Least k such that k*(Mersenne_prime(n)^2) + 1 is prime.at n=24A098819
- Eight rooks and one berserker on a 3 X 3 chessboard. G.f.: (1 - 2*x^2)/(1 - 4*x + x^2 + 2*x^3).at n=9A180144
- a(n) = n*(3*n^2 - 5*n + 3).at n=32A226450
- a(n) = n*(n + 1)*(17*n - 14)/6.at n=32A237617
- E.g.f.: C(x,q) = 1 + Integral S(x,q) * C(q*x,q) dx, such that C(x,q)^2 - S(x,q)^2 = 1, where C(x,q) = Sum_{n>=0} sum_{k=0..n*(n-1)/2} T(n,k)*x^n*y^k/n!, as an irregular triangle of coefficients T(n,k) read by rows.at n=29A322218
- Number of set partitions of [n] with distinct block sizes and one of the block sizes is 3.at n=12A328155