

A340303


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


1



10800, 12600, 54000, 75600, 148176, 162000, 264600, 324000, 609840, 453600, 529200, 793800, 444528, 648000, 1058400, 1323000, 1764000, 1620000, 2116800, 2646000, 2721600, 3704400, 3969000, 6403320, 4233600, 5292000, 4860000, 6223392, 7938000, 7408800, 8467200
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OFFSET

1,1


COMMENTS

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


LINKS

Table of n, a(n) for n=1..31.
Index entries for sequences related to prime signature


EXAMPLE

10800 = 2^4 * 3^3 * 5^2 is a term since 10800 and the next two numbers with the same prime signature as 10800, 16200 = 2^3 * 3^4 * 5^2 and 18000 = 2^4 * 3^2 * 5^3, have the same set of distinct prime divisors, {2, 3, 5}.


CROSSREFS

Subsequence of A340302.
Cf. A007947, A081761, A118914.
Sequence in context: A151935 A010089 A216142 * A093770 A190115 A203394
Adjacent sequences: A340300 A340301 A340302 * A340304 A340305 A340306


KEYWORD

nonn


AUTHOR

Amiram Eldar, Jan 03 2021


STATUS

approved



