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A036785 Numbers divisible by the squares of two distinct primes. 3
36, 72, 100, 108, 144, 180, 196, 200, 216, 225, 252, 288, 300, 324, 360, 392, 396, 400, 432, 441, 450, 468, 484, 500, 504, 540, 576, 588, 600, 612, 648, 675, 676, 684, 700, 720, 756, 784, 792, 800, 828, 864, 882, 900, 936, 968, 972, 980, 1000, 1008, 1044 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Not squarefree, not a nontrivial prime power and not in {squarefree} times {nontrivial prime powers}.

REFERENCES

CRC Standard Mathematical Tables and Formulae, 30th ed., (1996) page 102-105.

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

MATHEMATICA

Select[Range@ 1050, And[Length@ # > 1, Total@ Boole@ Map[# > 1 &, #[[All, -1]]] > 1] &@ FactorInteger@ #] (* Michael De Vlieger, Apr 25 2017 *)

dstdpQ[n_]:=Length[Select[Sqrt[#]&/@Divisors[n], PrimeQ]]>1; Select[ Range[ 1100], dstdpQ] (* Harvey P. Dale, Jan 15 2020 *)

PROG

(PARI) is(n)=my(f=vecsort(factor(n)[, 2], , 4)); #f>1&&f[2]>1 \\ Charles R Greathouse IV, Nov 15 2012

CROSSREFS

Cf. A005117, A025475.

Cf. A085986 (subsequence).

Sequence in context: A247381 A249726 A192026 * A286708 A114127 A322658

Adjacent sequences:  A036782 A036783 A036784 * A036786 A036787 A036788

KEYWORD

easy,nonn

AUTHOR

Alford Arnold

EXTENSIONS

More terms from Larry Reeves (larryr(AT)acm.org), Apr 03 2000

New name from Charles R Greathouse IV, Nov 15 2012

STATUS

approved

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Last modified May 31 22:45 EDT 2020. Contains 334756 sequences. (Running on oeis4.)