28033

Appears in sequences

• a(n) = (1/3)*(n^2 + 2*n + 3)*(n+1)^2.at n=16A014820
• Strong pseudoprimes to base 65.at n=18A020291
• Numbers n such that sum of primes dividing n (with repetition) is equal to the largest prime factor of n+1.at n=26A071863
• Quintisection of 1/(1-x^5-x^6).at n=19A099132
• Expansion of g.f. x*(x-1)*(x+1)^3/((2*x^3+x^2-1)*(x^4+1)).at n=27A107853
• 3-almost prime octagonal numbers.at n=22A129927
• Crystal ball sequence for the lattice C_4.at n=8A142993
• Right edge of triangular table A138612.at n=41A166019
• a(n) = 97*n^2.at n=17A174338
• Octagonal numbers with prime indices.at n=24A267144
• Numbers k such that (43*10^k - 421)/9 is prime.at n=20A276545
• Cyclops octagonal numbers: a(n) = n*(3*n-2) with one "zero" digit in the middle.at n=6A285767
• Composite numbers n such that E(n+1)+1 is divisible by n, where E(n) is the n-th Euler number (A122045).at n=22A287934
• Numbers m > 1 such that every prime divisor p of m satisfies s_p(m) = p.at n=17A324458
• Number of non-isomorphic T_0 set-systems covering a subset of {1..n} that are closed under intersection.at n=6A327013
• Number of 2 X 2 matrices with integer entries in [-n,n] that are diagonalizable over the complex numbers.at n=5A338413
• Number of compositions of 6*n-1 into parts 5 and 6.at n=15A373961
• a(n) = Sum_{k=0..floor(2*n/5)} binomial(k+1,2*n-5*k).at n=45A390020
• a(n) = Sum_{k=0..floor(3*n/5)} binomial(k+1,3*n-5*k).at n=30A391843