121841

Appears in sequences

• Numbers k such that the concatenation of k with 4*k gives a square.at n=20A115535
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 1, 0), (1, -1, 1), (1, 0, -1), (1, 1, 1)}.at n=9A149720
• a(n) = Product p_{n*i}^e_i if the prime factorization of n is Product p_i^e_i.at n=11A352028