20676
domain: N
Appears in sequences
- a(n) = C(n+2,3) + 2*C(n,2) + 2*(n-2).at n=46A034857
- E.g.f.: exp(exp(sinh(x))-1)-1.at n=8A053488
- 53 'Reverse and Add' steps are needed to reach a palindrome.at n=8A065320
- Expansion of e.g.f. (1+x)^(1/(1-log(1+x))).at n=8A088819
- a(n) = 4*n^5 + 10*n^4 + 13*n^3 + 11*n^2 + 5*n + 1.at n=5A094201
- Triangle read by rows: Each row is constructed by forming the partial sums of the previous row, reading from the right and at every third row repeating the final term.at n=42A099961
- Sequence of the next-to-last entries in the rows of A099961.at n=11A099963
- Number of 4-step S, E, and NW-moving king's tours on an n X n board summed over all starting positions.at n=32A187509
- Number of one-sided poly-[4.8^2]-tiles (holes allowed) with n cells (division into triangles is significant).at n=12A197466
- Number of n X 2 0..3 arrays with rows and columns lexicographically nondecreasing read forwards and nonincreasing read backwards.at n=38A201975
- Number of 5Xn binary arrays with rows lexicographically nondecreasing and columns lexicographically nondecreasing and row sums nondecreasing and column sums nonincreasing.at n=12A266938
- Number of nX4 binary arrays with row sums nondecreasing and columns lexicographically nondecreasing.at n=5A267241
- T(n,k)=Number of nXk binary arrays with row sums nondecreasing and columns lexicographically nondecreasing.at n=41A267245
- Number of 6Xn binary arrays with row sums nondecreasing and columns lexicographically nondecreasing.at n=3A267249
- Coefficients of orthogonal polynomials p(n, x) where p(n, 0) is A026150 with 1 prepended. Triangle read by rows, T(n, k) for 0 <= k <= n.at n=59A322941
- Numbers k such that 403*2^k+1 is prime.at n=29A323101
- Number of non-isomorphic set-systems with 4 sets each with n elements.at n=7A331715
- a(n) = Sum_k k*A333274(n,k).at n=12A333276
- Numbers k such that the k-th composition in standard order is an alternating permutation of {1..k} for some k.at n=39A349051
- a(n) = number of primes between n^2 and n^4.at n=22A380332