18914

Appears in sequences

• Numbers n such that 5^n+4^(n-1) is prime.at n=9A093793
• Expansion (1+x^3)/(1-x-x^7).at n=45A098527
• Consider 1-D random walk with jumps up to the third neighbor, i.e., set of possible jumps is {-3,-2,-1,+1,+2,+3}. Sequence gives number of paths of length n ending at origin.at n=7A117813
• Number of lines through at least 2 points of an 8 X n grid of points.at n=36A160848
• G.f.: exp( Sum_{n>=1} sigma(4n)*x^n/n ).at n=8A182820
• a(2) = 1, then (p-1)*(p-4)/2, with p = prime(n), n > 2.at n=43A200050
• Number of (w,x,y,z) with all terms in {0,...,n} and even range.at n=13A212889
• Irregular triangle read by rows: T(n,k) is the number of sensed 3-connected planar maps with n >= 4 faces and k >= 4 vertices.at n=62A239893
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 173", based on the 5-celled von Neumann neighborhood.at n=30A270467
• Numbers n such that uphi(n) = uphi(n+1), where uphi(n) is the unitary totient function (A047994).at n=27A287055
• Greatest integer k such that k/2^n < Euler's constant (0.577216...).at n=15A293352
• The integer k that minimizes |k/2^n - r|, where r = Euler's constant (0.577216...).at n=15A293354
• Numbers k such that 403*2^k+1 is prime.at n=27A323101
• Squares where A323811 gets stuck.at n=7A323815
• Numbers k such that iphi(k) = iphi(k+1), where iphi(k) is an infinitary analog to the Euler totient function (A091732).at n=23A326403
• Array read by antidiagonals: T(n,k) is the number of 3-connected triangulations of a disk up to orientation-preserving isomorphisms with n interior nodes and k nodes on the boundary, n >= 1, k >= 3.at n=34A341923
• Number of 3-connected triangulations of a quadrilateral up to orientation-preserving isomorphisms with n interior nodes.at n=6A341924
• Numbers k such that A384247(k) = A384247(k+1).at n=33A385743