24161

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has period 69.at n=23A020408
• A Wallis pair (x,y) satisfies sigma(x^2) = sigma(y^2); sequence gives y's for indecomposable Wallis pairs with x < y (ordered by values of x).at n=29A075769
• a(n) = A077503(n) - n*10^d, where d = n-A055642(n), A055642(n) = number of digits in n.at n=10A087095
• Number of ways to build a contiguous building with n LEGO blocks of size 1 X 4 on top of a fixed block of the same size so that the building is flat, i.e., with all blocks in parallel position and symmetric after a rotation by 180 degrees.at n=10A123785