26797

Appears in sequences

• Strong pseudoprimes to base 33.at n=11A020259
• Strong pseudoprimes to base 40.at n=21A020266
• Strong pseudoprimes to base 63.at n=22A020289
• Strong pseudoprimes to base 73.at n=13A020299
• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 98 ones.at n=32A031866
• a(n) = T(2*n, n), array T as in A047080.at n=10A047085
• Least positive integer multiples of angle x such that their direction cosines form a unit vector: Sum_{k>0} cos(a(k)*x)^2 = 1, where a(1)=1 and x=2/3.at n=30A080140
• a(n) = smallest M such that M is not divisible by prime(1), ..., prime(n), but is divisible by Sum_{i=1..n} (M mod prime(i)); or 0 if no such M exists.at n=18A106572
• a(n) = n^3 - 7*n + 7.at n=29A106734
• a(n) = (3*n+1)*(5*n+1).at n=42A144459
• For two strings of length n, this is the number of pairwise alignments that do not have an insertion adjacent to a deletion. (Duplicate of A047085.)at n=10A171155
• Positions of 2 in sequence A217916.at n=30A217918
• Numbers n such that (n^n-2)/(n-2) is an integer.at n=31A242787
• Composite numbers whose concatenation of their aliquot parts, in ascending order, is a palindrome.at n=37A249300
• Number of symmetric bargraphs having semiperimeter n (n>=2).at n=18A273905
• Number T(n,k) of entries in the k-th cycles of all permutations of [n] when cycles are ordered by decreasing lengths (and increasing smallest elements); triangle T(n,k), n>=1, 1<=k<=n, read by rows.at n=30A322384
• Number of entries in the third cycles of all permutations of [n] when cycles are ordered by decreasing lengths.at n=5A332852
• Triangle read by rows: T(n,k) is the number of labeled quasi-loop-threshold graphs on vertex set [n] with k components, for n >= 1 and 1 <= k <= n.at n=16A350746
• The number of regions formed when every pair of n points, placed at the vertices of a regular n-gon, are connected by a circle and where the points lie at the ends of the circle's diameter.at n=20A358782
• Let G_n denote the planar graph defined in A358746 with the addition, if n is odd, of the circle containing the initial n points; sequence gives the number of regions in G_n.at n=21A370976