54940

Appears in sequences

• Number of triangles a queen can make (starting anywhere) on an n X n board.at n=30A030117
• a(n) = n*(n+1)*(5*n+1)/6.at n=39A033994
• Numbers k such that (2^127-1)*2^k + 1 is prime.at n=18A098126
• Maximum possible number of subtrees of an n-node unrooted tree in which each node has maximum degree three (equivalently, rooted binary trees in which some internal nodes may have only one child). A subtree is a nonempty contiguous set of nodes, not necessarily including all descendants of the root.at n=24A124454
• Numbers k such that the sum of the first k consecutive prime numbers is pandigital (includes all 10 digits at least once).at n=31A228468
• G.f. A(x) satisfies: A(x) = 1/(1 - x*A(x)/(1 - x*A(x)/(1 - x*A(x)^2/(1 - x*A(x)^2/(1 - x*A(x)^3/(1 - x*A(x)^3/(1 - ...))))))), a continued fraction.at n=8A301418
• a(n) = (A350967(n)-1)/2.at n=2A350968
• Numbers k such that A003415(k) == A276085(k) (mod 5^5), where A003415 is the arithmetic derivative and A276085 is the primorial base log-function.at n=23A391865