23372

Appears in sequences

• a(1) = 3; a(n+1) = a(n)-th composite.at n=39A022451
• Number of step shifted (decimated) sequence structures using a maximum of three different symbols.at n=11A056392
• Numbers n such that 2*n^2 + 41 is a square.at n=10A133326
• a(n) is the smallest number which has in its English name the letter "o" in the n-th position, or -1 if no such number exists.at n=40A164789
• Arises from color-symmetrized counting of tensor invariants.at n=5A232213
• a(0) = 5, a(1) = 2; for n>1, a(n) = 2*a(n-1) + a(n-2).at n=11A276849
• Expansion of Product_{k>=1} (1 - p(k)*x^k), where p(k) = number of partitions of k (A000041).at n=28A304785
• One half of the sum over all permutations of [n] of the absolute difference between the length of the longest increasing subsequence and the length of the longest decreasing subsequence.at n=7A321277
• Greatest integer whose square root is less than or equal to Sum_{j=0..n} sqrt(j).at n=37A338277
• Irregular table read by rows: T(n,k) is the number of k-gons, k>=2, among all distinct circles that can be constructed from a point on the origin and n equally spaced points on each of the +x,-x,+y,-y coordinates axes when each pair of points is connected by a circle and where the points lie at the ends of the circles' diameter.at n=51A362236