51330

Appears in sequences

• a(n) = n*(n+1)*(2*n+1).at n=29A055112
• a(n) = p*(p + 1)*(2*p + 1) where p is the n-th prime.at n=9A098996
• Squarefree positive integers of the form u*v*(u^2-v^2) for some integer u,v.at n=25A147779
• Integer areas of integer-sided triangles where at least one of the three altitudes is of prime length.at n=28A256579
• Triangle read by rows: T(n,k) is the number of strongly connected oriented graphs on n labeled nodes with k arcs, n >= 1, k=0..n*(n-1)/2.at n=33A350731
• Area of the unique primitive Pythagorean triple whose inradius is A000032(n) and such that its long leg and its hypotenuse are consecutive natural numbers.at n=7A380824
• Area of the unique primitive Pythagorean triple (a,b,c) such that (a-b+c)/2 = A002378(n) and its long leg and hypotenuse are consecutive natural numbers.at n=5A385187
• a(n) is the least number that is the area of a primitive Pythagorean triangle and is the sum of 2*n consecutive primes.at n=17A387673