40200

Appears in sequences

• a(n) is the concatenation of n and 5n.at n=39A019553
• Differences of two factorial numbers.at n=24A051949
• Number of subsets of {1, ..., n} with no four terms in arithmetic progression.at n=17A066369
• Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=2, r=3, I={-1,0}.at n=25A080008
• a(n) = (1/2)*(n^4 + 11*n^3 + 53*n^2 + 97*n + 54).at n=15A129026
• Number of partitions where the number of 1's and 2's are equal.at n=54A174455
• Triangle read by rows: T(n,k) is the number of permutations of [n] having k adjacent 4-cycles (0 <= k <= floor(n/4)), i.e., having k cycles of the form (i, i+1, i+2, i+3).at n=22A177252
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k as the last entry in the first block (1<=k<=n).at n=38A177263
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k as the first entry in the last block (1<=k<=n).at n=42A177264
• Ordered differences of factorials.at n=25A204930
• Sum of positive even numbers up to n^2.at n=19A235367
• Triangle read by rows: Cayley's numbers phi(m,n) (m,n>=0). Row m contains phi(m,0), phi(m-1,1), phi(m-2,2), ..., phi(0,m).at n=41A260338
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 377", based on the 5-celled von Neumann neighborhood.at n=38A271463
• Oblong numbers n such that n - 1 and n + 1 are both semiprime.at n=36A276565
• a(n) is the number of cyclic permutations with at most two descents.at n=12A303117
• a(n) is the number of cyclic permutations with at most 2 ascents.at n=12A304200
• Lexicographically earliest sequence of distinct positive integers with no finite subset summing to a factorial number (A000142).at n=33A353969
• E.g.f. satisfies A(x)^A(x) = 1/(1 - x)^(x^3/6).at n=10A356913
• Number of permutations of [n] having exactly one adjacent 4-cycle.at n=11A369098
• Triangle read by rows: T(n,k) = number of permutations of [n] having exactly one adjacent k-cycle. (n>=1, 1<=k<=n).at n=58A370527