26875

Appears in sequences

• a(n) = (2*n - 7)*n^2.at n=25A015242
• Expansion of 1/(1-x^3-x^4-x^5-x^6-x^7-x^8-x^9).at n=32A017822
• Triangle T(n,k) of the number of strongly connected digraphs on n labeled nodes and with k arcs, k=0..n*(n-1).at n=32A057273
• Odd composites (including 1 in the count) where the number 3 mod 4 equals the number 1 mod 4.at n=6A093181
• Triangle read by rows: T(n,k) is the number of directed column-convex polyominoes of area n and having k cells in the shortest column (1<=k<=n).at n=66A121301
• Number of directed column-convex polyominoes having at least one 1-cell column.at n=11A121302
• Numbers k such that k and k^2 use only the digits 2, 5, 6, 7 and 8.at n=26A137111
• Number of involutions of length 2n which are invariant under the reverse-complement map and have no decreasing subsequences of length 8.at n=8A145870
• Number of 5-step S, E, and NW-moving king's tours on an n X n board summed over all starting positions.at n=24A187510
• a(n) = Sum_{k=0..n}(binomial(n-1,n-k)*binomial(n+k-1,n-k)).at n=8A262442
• Numbers k such that (28*10^k + 173)/3 is prime.at n=27A272537
• Odd numbers m such that there exists no k for which the denominator of d(k)/k = m where d(k) is the number of divisors of k (A000005).at n=22A353320