19844

Appears in sequences

• a(n) = (2*n - 3)n^2.at n=22A015238
• Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite MON = Montesommaite (K,Na)9[ Al9Si23O64 ] . 10 H2O.at n=13A019178
• n! has a palindromic prime number of digits.at n=29A035067
• Least m such that sqrt(m) has a period 2n continued fraction expansion whose palindrome part concatenates to a palindromic prime.at n=22A072135
• Number of simple graphs g on n nodes with |Aut(g)| = 24.at n=9A095855
• a(n) = 4*(5*n^2 - 5*n + 1).at n=31A193448
• Number of (n+1) X (n+1) -7..7 symmetric matrices with every 2 X 2 subblock having sum zero and three or four distinct values.at n=3A211446
• Number of partitions p of n such that max(p)-min(p) = 9.at n=40A218572
• Number of nonequivalent ways to select 3 disjoint point triples from an n X n X n triangular point grid, each point triple forming a 2 X 2 X 2 triangle.at n=8A289230
• Number of regions in a regular drawing of the complete bipartite graph K_{n,n}.at n=18A290131
• Squares where knight moving to a lowest unvisited square on a spirally numbered board will have no available moves.at n=18A323714
• Number of parts in all n-times partitions of n.at n=6A327619
• a(n) = Sum_{i=1..n} sigma(i)*sigma(i+1), where sigma(n) = A000203(n) is the sum of the divisors of n.at n=27A330322
• Numbers k such that k and k+1 both have more nonunitary than unitary prime divisors (A348121).at n=22A348122
• Greatest positive integer whose reversed (weakly decreasing) prime indices have weighted sum (A318283) equal to n.at n=47A359683
• Irregular table read by rows: T(n,k) is the number of k-gons, k>=3, among all distinct circles that can be constructed from the 4 vertices and the equally spaced 4*n points placed on the sides of a square, using only a compass.at n=53A372980
• E.g.f. satisfies A(x) = 1/(1 - A(x) * (exp(x*A(x)) - 1))^2.at n=4A377490
• Smallest k for which a chain of linked rods of length 1, ..., k can be folded in half in exactly n dictinct ways.at n=32A390056