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%I #7 Feb 29 2020 15:03:56
%S 1,25,85,145,221,265,365,481,545,685,841,925,1105,1405,1513,1625,1985,
%T 2245,2665,2813,2965,3281,3445,3785,3961,4141,4325,4705,4901,5305,
%U 5513,5725,5941,6161,6385,6613,6845,7081,7565,7813,8065,8321,8845,9113,9385
%N Nonprimes of the form (k^2+1)/2.
%C Or, 1 together with composite numbers of the form i^2+(i+1)^2. See A012132. - _N. J. A. Sloane_, Feb 29 2020
%C A166080 U A027862 = A001844.
%F a(n) = 2n^2 + O(n^2/log n). - _Charles R Greathouse IV_, Mar 21 2014
%e a(1)=(1^2+1)/2=1; a(2)=(7^2+1)/2=25.
%Y Cf. A001844, A027862, A012132, A141468.
%K nonn,easy
%O 1,2
%A _Juri-Stepan Gerasimov_, Oct 06 2009
%E Replaced 6261 by 6161 - _R. J. Mathar_, Oct 07 2009
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