20299

Appears in sequences

• Class numbers of quadratic fields.at n=16A001985
• a(n) = C(n+2,3) + C(n,3) + C(n-1,3).at n=34A006004
• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 57 ones.at n=0A031825
• Binomial transform of A001371.at n=11A054195
• Number of hexagonal regions in regular n-gon with all diagonals drawn.at n=47A067153
• Number of unlabeled rooted trees with at most n nodes.at n=12A087803
• a(n) = least k such that 3^k mod k = 2^n.at n=11A128148
• Number of nX1 0..3 arrays with no more than floor(nX1/2) elements unequal to at least one horizontal or vertical neighbor, with new values introduced in row major 0..3 order.at n=14A222372
• T(n,k)=Number of nXk 0..2 arrays with rows and antidiagonals unimodal and columns nondecreasing.at n=37A223918
• Number of 2 X n 0..2 arrays with rows and antidiagonals unimodal and columns nondecreasing.at n=7A223919
• T(n,k) = Number of n X k 0..2 arrays with rows unimodal and columns nondecreasing.at n=37A224190
• T(n,k) = number of n X k 0..2 arrays with rows, diagonals and antidiagonals unimodal and columns nondecreasing.at n=37A224262
• Numbers n such that there is an integer k with the property that k^tau(n) = sigma(n).at n=16A225239
• a(n) = Fibonacci(p) mod p^2, where p = prime(n).at n=45A236395