18208

Appears in sequences

• a(1) = 3; for n>0, a(n+1) = a(n) + floor((a(n)-1)/2).at n=23A003312
• Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 67.at n=34A031565
• E.g.f.: -log(1-x+log(1-x)).at n=6A052808
• Numbers k such that (k^2 - 14)/2 is a square.at n=10A077447
• Number of polyhexes with 24 hexagons, C_(2v) symmetry and containing n carbon atoms.at n=11A123284
• Number of cycles in range [A014137(n-1)..A014138(n-1)] of permutations A130919/A130920.at n=11A130967
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 0), (0, 0, 1), (1, -1, -1), (1, 1, -1)}.at n=10A148329
• Coefficients of polynomials (in descending powers of x) P(n,x) := 1 + P(n-1,x)^2, where P(1,x) = x + 1.at n=25A158985
• Number of permutations of 1..n containing the relative rank sequence { 145263 } at any spacing.at n=3A159114
• Number of permutations of 1..n containing the relative rank sequence { 243615 } at any spacing.at n=3A159154
• Number of permutations of 1..n containing the relative rank sequence { 246513 } at any spacing.at n=3A159159
• Number of binary strings of length n with equal numbers of 001 and 110 substrings.at n=16A164145
• Consider the base-3 Kaprekar map n->K(n) defined in A164993. Sequence gives numbers belonging to cycles, including fixed points.at n=14A164998
• Consider the base-3 Kaprekar map n->K(n) defined in A164993. Sequence gives numbers belonging to cycles of length greater than 1.at n=10A165000
• Consider the base-3 Kaprekar map n->K(n) defined in A164993. Sequence gives least elements of each cycle, including fixed points.at n=8A165002
• Consider the base-3 Kaprekar map n->K(n) defined in A164993. Sequence gives least elements of each cycle of length > 1.at n=4A165004
• Smallest member of cycle corresponding to n-th term of A165009.at n=8A165010
• The number of subsets X of Zn such that for all u, v in X, u+v is not in X.at n=26A206702
• Number of (n+3) X (1+3) 0..3 white square subarrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, and upper left element zero.at n=6A230942
• Number of (n+3)X(7+3) 0..3 white square subarrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, and upper left element zero.at n=0A230948