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A062739 Odd powerful numbers. 3

%I

%S 1,9,25,27,49,81,121,125,169,225,243,289,343,361,441,529,625,675,729,

%T 841,961,1089,1125,1225,1323,1331,1369,1521,1681,1849,2025,2187,2197,

%U 2209,2401,2601,2809,3025,3087,3125,3249,3267,3375,3481,3721,3969,4225

%N Odd powerful numbers.

%C Smallest term of this sequence not also in A075109 is 675, followed by 1125. - _Alonso del Arte_, Nov 22 2011

%D R. K. Guy, Unsolved Problems in Number Theory, B16

%H Zak Seidov, <a href="/A062739/b062739.txt">Table of n, a(n) for n = 1..10000</a>

%H W. A. Sentance, <a href="http://www.jstor.org/stable/2320553">Occurrences of consecutive odd powerful numbers</a>, Amer. Math. Monthly, 88 (1981), 272-274.

%F It is not true that a(n) = A001694(2n-1).

%e Consecutive-odd examples from Sentance: {25,27},{70225,70227},{189750625,189750627}

%t Powerful[n_Integer] := (n ==1) || Min[Transpose[FactorInteger[n]][[2]]]>=2; Select[Range[5000],OddQ[ # ]&&Powerful[ # ]&] (* _T. D. Noe_, May 04 2006 *)

%Y Cf. A001694, A060355, A060859, A060860.

%Y Cf. A076445 (consecutive odd powerful numbers).

%K nonn

%O 1,2

%A _Labos Elemer_, Jul 12 2001

%E Checked by _T. D. Noe_, May 04 2006

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Last modified November 17 23:26 EST 2019. Contains 329242 sequences. (Running on oeis4.)