A158915 Least number k such that there is an m > k with sigma_n(k) = sigma_n(m).

2, 6, 6, 184926

Offset: 0

Author

T. D. Noe, Mar 30 2009

Keywords

• more
• nonn

Comments

It is easy to verify the first three terms using sequences A000005, A000203, and A001157. The first term of A131908 gives a(3). The a(4) term is greater than 10^8. Does a(n) exist for all n?

Examples

			sigma_0(2)=sigma_0(3); sigma_1(6)=sigma_1(12); sigma_2(6)=sigma_2(7); sigma_3(184926)=sigma_3(194315).