35712

Appears in sequences

• Triangle T(n,k) (n >= 2, 1 <= k <= n-1) giving number of non-crossing trees with n nodes and height k.at n=52A072248
• Structured truncated tetrahedral numbers.at n=26A100156
• Triangle read by rows: T(n,k) (0 <= k <= n) is the number of Delannoy paths of length n, having k return steps to the line y = x from the line y = x+1 or from the line y = x-1 (i.e., E steps from the line y = x+1 to the line y = x or N steps from the line y = x-1 to the line y = x).at n=41A110107
• Table B(m,n), read by antidiagonals, where B(m,n) is the number of ways integers 1,..,m*n can be put into an m X n grid so that every adjacent (NESW) pair of integers are coprime.at n=22A116542
• Table B(m,n), read by antidiagonals, where B(m,n) is the number of ways integers 1,..,m*n can be put into an m X n grid so that every adjacent (NESW) pair of integers are coprime.at n=26A116542
• Smaller member of an infinitary amicable pair.at n=10A126169
• Infinitary amicable numbers.at n=19A127664
• Records in A000118.at n=44A128690
• a(n) = 81*n^2 - 9.at n=20A157909
• Numbers m such that m = s|t = phi(s)*sigma(t) for some numbers s and t, where "|" denotes concatenation.at n=2A159000
• Sums of adjacent amicable numbers, a(n) = A063990(2n-1) + A063990(2n).at n=7A161005
• Number of 3 X 3 semimagic squares with distinct positive values < n. In a semimagic squares the row and column sums must all be equal (the "magic sum").at n=7A173546
• The sum of the two numbers in an amicable pair, A002025(n) + A002046(n).at n=7A180164
• Numbers with prime factorization pq^2r^7.at n=13A190466
• Molecular topological indices of the graph join C_n + C_n of cycle graphs.at n=15A192848
• Number of (w,x,y,z) with all terms in {1,...,n} and |x-y|>=|y-z|.at n=16A212682
• Number T(n,k) of permutations of [n] with exactly k (possibly overlapping, cyclic wrap-around) occurrences of the consecutive step pattern UDU (U=up, D=down); triangle T(n,k), n>=0, 0<=k<=floor(n/2), read by rows.at n=29A232933
• Number of irregular spiral (expanded spiral) appearing with n center points.at n=7A236755
• The sum (in nondecreasing order) of the two numbers in an amicable pair.at n=7A259953
• Numbers k such that the determinant of the Vandermonde matrix of their digits is equal to phi(k), the Euler totient function of k.at n=15A307587