153181

Appears in sequences

• Strong pseudoprimes to base 23.at n=31A020249
• Triangular numbers such that the product of digits is also a (positive) triangular number.at n=25A069077
• Smallest triangular number beginning with the n-th triangular number other than itself.at n=16A072517
• The sequence solves the following problem: find all the pairs (i,j) such that i divides 1+j+j^2 and j divides 1+i+i^2. In fact, the pairs (a(n),a(n+1)), n>0, are all the solutions.at n=9A101368
• Triangular numbers T such that T+10 is the next prime after T.at n=22A129540
• Triangular numbers for which the product of the digits is a nonzero hexagonal number.at n=12A185211
• Smallest triangular numbers whose decimal expansion begins (nontrivially) with n-th triangular number.at n=16A229235
• a(n) = (m(n)^2 + 3)*(m(n)^2 + 7)/32, where m(n) = 2*n - 1.at n=23A336535
• Triangular numbers that are the sum of two distinct nonzero triangular numbers in exactly two ways.at n=25A350368
• Array of triples (x,y,z) satisfy the Diophantine equation (x+y)^2 + (y+z)^2 + (z+x)^2 = 12*x*y*z, 1 <= x <= y <= z. (sorted by z).at n=44A351372
• Array of triples (x,y,z) satisfy the Diophantine equation (x+y)^2 + (y+z)^2 + (z+x)^2 = 12*x*y*z, 1 <= x <= y <= z. (sorted by z).at n=49A351372
• Sorted list of nonzero numbers x, y, z that occur in solutions to the equation (x + y)^2 + (y + z)^2 + (z + x)^2 = 12*x*y*z.at n=14A357749