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

1,1

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, ...

Links

Table of n, a(n) for n=1..10.

Index entries for sequences related to prime signature

Example

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}.

Crossrefs

Subsequence of A340302 and A340303.

Cf. A007947, A081761, A118914.

Sequence in context: A203930 A215999 A219334 * A364903 A210352 A321828

Adjacent sequences: A340301 A340302 A340303 * A340305 A340306 A340307

Keyword

nonn,more

Author

Amiram Eldar, Jan 03 2021

Status

approved