A340304 Numbers k such that k and the next three numbers after k with the same prime signature as k also have the same set of distinct prime divisors as k.

529200, 1058400, 2646000, 3704400, 5292000, 9720000, 15876000, 22226400, 18522000, 31752000

Offset: 1

Author

Amiram Eldar, Jan 03 2021

Keywords

• nonn
• more

Comments

Numbers k such that A007947(k) = A007947(A081761(k)) = A007947(A081761(A081761(k))) = A007947(A081761(A081761(A081761(k)))).

The analogous sequence with the next four numbers after k begins with 2646000, 15876000, ...

Examples

			529200 = 2^4 * 3^3 * 5^2 * 7^2 is a term since 529200 and the next three numbers with the same prime signature as 529200, 793800 = 2^3 * 3^4 * 5^2 * 7^2, 882000 = 2^4 * 3^2 * 5^3 * 7^2, and 1234800 = 2^4 * 3^2 * 5^2 * 7^3, have the same set of distinct prime divisors, {2, 3, 5, 7}.
		

Links

• Index entries for sequences related to prime signature

Crossrefs

Subsequence of A340302 and A340303.

Cf. A007947, A081761, A118914.