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A157942 Numbers n divisible by the largest prime <= sqrt(n), A007917(A000196(n)). 5

%I #10 Jul 25 2024 14:08:56

%S 4,6,8,9,12,15,18,21,24,25,30,35,40,45,49,56,63,70,77,84,91,98,105,

%T 112,119,121,132,143,154,165,169,182,195,208,221,234,247,260,273,286,

%U 289,306,323,340,357,361,380,399,418,437,456,475,494,513,529,552,575,598

%N Numbers n divisible by the largest prime <= sqrt(n), A007917(A000196(n)).

%C Includes squares of primes (A001248; exactly the cases where we have "=" in the definition) and products of pairs of consecutive primes (A006094) as subsequences.

%t Select[Range[4,599],IntegerQ[#/Prime[PrimePi[Sqrt[#]]]]&] (* _Jayanta Basu_, May 03 2013 *)

%o (PARI) for( n=4,999, n % precprime(sqrtint(n)) || print1(n","))

%K nonn

%O 1,1

%A _M. F. Hasler_, Mar 09 2009

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Last modified August 19 13:48 EDT 2024. Contains 375302 sequences. (Running on oeis4.)