19893

Appears in sequences

• 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 94.at n=34A031592
• First of three consecutive Ulam numbers (A002858) in arithmetic progression with difference 22.at n=12A068856
• G.f. satisfies: A(x) = 1 + x*(1-x-x^2)*A(x) + x^2*(3+2*x)*A(x)^2.at n=9A119372
• 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, 1), (-1, 0, 1), (0, 0, -1), (0, 1, -1), (1, 1, 1)}.at n=8A149696
• Demi-tribonacci numbers (rounding down): a(0)=a(1)=0, a(2)=2; a(n) = floor( (a(n-1)+a(n-2)+a(n-3))/2 ).at n=51A180234
• Number of rooted trees with n nodes and omega-valency 2.at n=14A193487
• a(n) = n-1 for n <= 4, otherwise if n is even then a(n) = a(n-5)+2^(n/2), and if n is odd then a(n) = a(n-1)+2^((n-3)/2).at n=27A200310
• Solution to the problem of finding the number of comparisons needed for optimal merging of 3 elements with n elements.at n=40A239100
• Number of n-node unlabeled rooted trees with thinning limbs and root outdegree (branching factor) 7.at n=13A244708
• Number of nX2 0..2 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly three mistakes.at n=4A278650
• Number of nX5 0..2 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly three mistakes.at n=1A278653
• T(n,k)=Number of nXk 0..2 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly three mistakes.at n=16A278656
• T(n,k)=Number of nXk 0..2 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly three mistakes.at n=19A278656
• Number of non-condensed integer partitions of n into parts > 1.at n=49A370804
• Numbers that can be written in exactly two different ways in the form described by A387302.at n=7A387898