A302490 Fewest number of distinct prime factors in any product of a_1*a_2*...*a_t where n = a_1 < a_2 < ... < a_t = A006255(n) and the product is square.
0, 2, 2, 1, 2, 2, 2, 3, 1, 3, 3, 3, 3, 4, 3, 1, 2, 2, 2, 3, 3, 3, 2, 2, 1, 3, 4, 3, 2, 4, 2, 3, 5, 4, 4, 2, 3, 3, 3, 3, 3, 3, 3, 4, 3, 3, 3, 3, 1, 4, 4, 5, 3, 4, 5, 3, 4
Offset: 1
Examples
a(14) = 4 because 14 * 15 * 16 * 18 * 20 * 21 has four distinct prime factors (2, 3, 5, and 7) and no other square product of a strictly increasing sequence starting at 14 and ending at 21 has fewer distinct prime factors.
Comments